Going quite well sales wise, much better than PC and Mac!
I'm very likely to be doing more iPhone games (really enjoying iPhone development), and hopefully Android too. I can't see myself doing games under contract for other companies though, not unless they're prepared to throw massive amounts of cash at me (unlikely). I really like the idea of being free to make the kind of games that I truely believe in, and make them as best I can, and I think I've found working for other companies is often very restricting, and creatively restricting too.
So, just seems better to me, to do my own thing, probably will work out much better financially to do so, and more importantly, it's so much more creatively rewarding.
Deffo follow me on twitter or signup to my newsletter, if you want to keep in touch (newsletter and twitter info both on www.qwak.co.uk
As for Nitro, I'd need to dig the contract out and check it over; it maybe that I'd just do a top down racer and not call it Nitro..