Now this list has gone through a lot of tweaking, and a few tips from various people and places, namely the lads down at my local GW store, where someone plays a very succesful Thousand Sons army there. This is my latest incarnation as I've finally gotten it to a legal 1500 points!

Thousand Sons List

HQ:
Chaos Lord
Mark of Tzeentch, Disc of Tzeentch, Bolt of Change, Dark Blade, Spiky Bits
165 Points

Elites:
4 Rubric Terminators and Aspiring Champion w/
Inferno Bolts, Spiky Bits, Daemonic Mutation, Power Fist
268 Points

Troops:
8 Rubric Marines with Aspiring Champion w/
Power Fist, Close Combat Weapon, Doombolt, Daemonic Mutation, Daemonic Visage, Spiky Bits
269 Points

8 Rubric Marines with Aspiring Champion w/
Power Fist, Close Combat Weapon, Doombolt, Daemonic Mutation, Daemonic Visage, Spiky Bits
269 Points

8 Rubric Marines with Aspiring Champion w/
Power Fist, Close Combat Weapon, Doombolt, Daemonic Mutation, Daemonic Visage, Spiky Bits
269 Points

5 Flamers of Tzeentch
115 Points

Heavy Support:
Chaos Predator
Twin-linked Lascannon, lascannon side sponsons
145 Points

Total:
1500 Points

A lot of people think Thousand Sons are no good in combat, but I think they potentially are very devistating. With tooled up aspiring champions holding power fists fighting behind the cover of 16 wounds, they should fair rather well. Couple that with hails of bolter fire and doombolts, the lascannons to take out heavy armoured threats, and the hovering lord to get to where he needs to be. That's the basic idea of the army, and hopefully I can pull it off.