I played my first battle with the new Imperial Guard codex yesterday against Jim Barr's Word Bearer chaos space marines. We played the annihilation mission and I lost.
here is a link to Jim's Battle report
http://bootae.ibforums.com/index.php?showtopic=11127my List was
ArchMagos Biologis (Inquisitor lord)
terminator armor, Psychic hood,force weapon,psycannon
2 mystics
1 familiar
1 sage
3 heavybolter servitors
Calidus assassin
Magos Biologis (Psyker Primaris)
A Vendetta with sponson heavybolters
Enginseer with 2 plasma cannon servitors
Veteran Skitari (vet squad)
Sgt power weapon/plasma pistol
3 meltaguns
6 shotguns
Biologis Experimental Squad (Psyker Battle squad) x2
Overseer and 9 psykers
Chimera multilaser, hull heavy bolter, searchlight, smoke, pintle stormbolter, extra armor, hunterkiller missle
Skitari platoon (infantry platoon)
Platoon leader power weapon
Commissar power weapon
3 plasmaguns
medic
Infantry squad x2
sgt power weapon
commissar power weapon
grenade launcher
autocannon
Special weapon squad
3 flamers
Heavy weapon squad
3 las cannons
My main plan was to test out some of the new units in the codex and try to see if the Calidus/psyker battle squads combo would work. the Calidus combo works by the Psykers using weaken resolve to lower a target units leadership and then the Calidus' Neural shredder will be able to wound them easier and possibly cause instant death. The first test run failed, mostly because the Calidus didn't arrive from reserve until turn five. By then one psyker squad had fled the table and the other only had been killed by a Defiler. When the calidus did arrive the game was basically over but she got a shot off with the shredder and got a couple marines, then charged in and got a couple more, but not enough to make her points. I was able to move jim's vindicator out of cover before the game started.
I mounted the vet squad in the vendetta and it also was slow in arriving but when they did show the vets helped burn down a chaos terminator squad and then destroy a dreadnought. The vendetta shot some and didn't do anything.
The inquisitor/ mystic combo was able to get their free shots on several units deepstriking but I don't think they made their points back.
The Psyker Primaris survived the chimera he was riding in being destroyed by a vindicator's demolisher cannon and then he destroyed a Wordbearer rhino killing several wordbearers. Unfortunately the other Wordbearer rhino moved up and the squad inside burnt him down a couple turns later.
The Enginseer and his plasma cannon buddies burnt up a chunk of a chosen squad. this earned him the privilege of have a Chaos terminator squad deep strike near him just to put him down. The terminator killed both of his servitors but he was still alive. Then I picked up another lesson, an Enginseer should never charge a chaos terminator squad, even if they just killed his servitors. They have lots of power weapons and go first.
The heavy weapon team stayed on the third floor of a building and took potshots at several things. i think they made their points but I probably need to field more of them.
The Special weapon team ran up the middle to certain doom, but after the Primaris destroyed a rhino and left a squad of marines swinging in the breeze, they were able to flame the marines and kill a couple. they made them a broke even on points. They were all gunned down the next turn but at least they were able to kill someone.
The Skitari platoon had mixed results. One squad stayed on the second floor of a building below the heavy weapon team and shot up whatever came into range. The second squad also up in a building was able to fire on the chosen squad as it advanced. They ended up assaulted by a daemon pack, but because of the stubborn commissar was able to fight for three rounds of combat. The chosen squad joined the fight and that was the end. The command squad ended up taking a demolisher hit killing 2 plasma gunners. they fired a few pot shots but not much effect. Another template hit killed the last plasmagunner, then the lieutenant failed his morale roll and was executed by the commissar. The last commissar and medic ended the game assaulting a defiler for a little krak grenade action and were squashed by the Defiler. The new Commissars are two edged. the stubborn will keep a unit in the fight but can also lose that power weapon equipped sgt/Lt.
The Psyker battle squads had a decent show for the game. The calidus no show till the end of the game kept me from trying out the combo but maybe next time. One squad was cut in half when its chimera was destroyed and ended the game running off of the table after taking more casualties. The second squad lasted longer, even damaging the defiler. The defiler ended up destroying the chimera. Once on foot, a demolisher cannon shot from the vindicator scattered onto the defiler and the squad killing several of the psykers.
Some final thoughts on the game. Of the 1850 points of the list the 2 psyker squads and the calidus were 520 points. The combo could make its points back but it will take good circumstances for it to get the gimmick off. I think a more reliable use of the Psyker squad would be to add some pinning weapons to the list. Then once I lower a squads leadership with the psykers to pin the squad in front of allot of guns. I could add some more anti-tank to the list. I had a hard time putting Jim's vehicles down, the only answer for that is more guns. I had a good time and I am thinking about adding a Company commander to get access to more orders.
Here are the lads in the Basement of Heaped Miniatures. Patrick on the left and John right forward and Charles in the corner.
The Traitor T34/85s advance on the Soviet lines.
Table view of the oncomming horde.
IS-2 stare down the T34s, right before a german flame tank came up from the rear and destroyed them.
The army in all its glory. The vendetta proxy is a Star wars die cast flyer. I picked up four of then years ago planning to use them as Valkyries in apocalypse games. Now they are in the codex.
The Psyker Battle Squads. I used all genestealer hybrids for the psykers and an Arbite Proctor for the overseer.
These are the skitari guardsmen I converted up years ago. They were originally built for Tim Huckleberry's homegrown Adeptus Mechanicus codex.
Heavy weapon squad from my no longer usable heavy weapon platoon. The funny thing about the new codex is that I can field allot more guns in the current codex than I could with the heavy weapon platoons in the last codex.
My Psyker Primaris. The model is a conversion I built for a special character in Tim Huckleberry's Genestealer cult armylist published in citadel journal. I have an old Psyker Primaris model painted up but I thought it would look more stylish and match the psykers. 
Here is my Veteran Squad. these are a conversion I did for an Elysian drop troop army I built based on the army list published in White Dwarf. Again another army that went the way of the dodo when the last codex was released. The models are made from catachan legs, a trimmed spacemarine torso, spacemarine arms, scout biker shotguns and sentinel pilot heads.
My Inquisitor retinue and the Enginseer with his plasma cannon servitors.
