The deck forum is a little slow the last few days, so here's something for the weekend.
The three new Skaven allow you to take them from a side strategy to center-stage. Orc/Skaven rush is decent build that may or may not be slightly better than mono-Orc beats, but in any case plays fairly similarly. Chaos/Skaven has to play a bit differently than either the Orc version or non-Skaven Chaos decks; it can't get the huge attack pools that the Orcs can, but it's better at keeping its important-but-fragile attackers (Thanquol, Gutter Runners) alive, thanks to Horrific Mutation, which locks out small defenders and lets you kill mid-sized defenders with the Globadiers or remvoal. Here's my version:
Units: 27
3 Savage Gors (2-C)
3 Savage Marauder (3-C)
3 Bloodsworn (4-C)
3 Clan Rats (2)
3 Gutter Runners (2)
3 Clan Moulder's Elite (2)
3 Poisonwind Globadiers (3)
3 Greyseer Thanquol (3)
3 Rat Ogres (4)
Support: 14
3 Warpstone Excavation (0)
2 Cloud of Flies (0-C)
3 Contested Village (1)
3 Horrific Mutation (1-C)
3 Warpstone Meteor (3-CC)
Tactics: 9
3 Seduced By Darkness (0-C)
3 Blood for the Blood God (2-CC)
3 Flames of Tzeentch (X-CCC)
While your attacks are difficult to defend, you aren't that good at defending, either; so, you have to rely on Seduced By Darkness and Blood for the Blood God to deal with attackers -- not too much of a drawback, since both get rid of their targets for your next turn, too. Flies and Flames give you some all-purpose removal.
Another way to go would be to drop the 3 Bloodsworn, 2 Cloud of Flies, and probably a Flames of Tzeentch for 3 Chittering Horde and 3 Warp Lightning Guns. The Guns aren't bad when your attacks can't be defended, and Chittering Horde can find that all-important first Thanquol or Rat Ogre. You're giving up some Chaos icons, though, so you may have to pay for the odd loyalty cost. Animosity might also be worth considering if you go for less Chaos stuff.
Anybody go a different direction with Chaos/Skaven?