I love my necrons, and Tau are a fantastic race that would be incredibly fun to play, But I gotta say that for the first additional race, IG are the way to go. they could have a much higher cap for vehicles, Maybe even a higher population cap... I can see it working beautifully, and with the story as well.
Honestly my favourite races are already going to be implemented at launch. I'm not particularly bothered who makes it in next, but if I had to choose it'd be between Dark Eldar and Imperial Guard. DE have some interesting concepts behind them that makes them more than just 'Eldar... but evil!!!' to me. Imperial Guard because everybody loves a commissar. I already thought the Tau and Necron lore was kind of weak, and playing too much Dawn of War has only solidified my hatred of these two races. I guess that mean's they're doing it right though eh?
I think that they should do like in Dawn of Wars, releasing at once two different new factions, so after launching it some balance would have been mainteined
I'd have to go necrons. As it's been said, the dark eldar are to Eldar what chaos marines are marines. Plus I just have a feeling that guards would be horribly weak compared to the other races. The other race options can match one another fairly well, at least going by the novels, but I know of no fluff where a guard can go toe to toe with a marine. Plus I like how different the necrons would be compared to other races. A wraith as a scout instead of rangers or path finders. Flayed ones instead of kroot or assault troopers. I just think it would be a nice difference to set it apart. In other news though... Daemons would be interesting, though I know it's not an option, it would still be interesting to see.
I voted for the Tau Empire as the Tau are after Space Marines and Eldar my favorite race. Their holding together, mentality and such is quite interesting... also I like how fast they adapt to new situations and I love their pew-pew weapons ^^
