I'm going to play soldier again. In the first game i played a '3 pure class' squad, taking Tali and Liara with me on every mission after i got them.
I really liked this setup and i'm planning to play ME2 the same way, so i'll definitely be taking Tali again but since Liara is not available as a squad mate this time around i will have to choose a replacement. Subject Zero appears to be a pure biotic build so she might be a good choice, but i might take Thane since he has biotics and also good with sniper rifles etc...
Looking forward to friday now, i am hoping that we can start the pre-load on Steam at midnight tonight (US got 48hour preload).
One thing i forgot to mention is that i play ME with squad powers turned off, meaning i am in control of them using tech/biotic abilities. This makes the game so much more fun IMO!