This question would get side-tracked half way with talk of VR (image stabilisation) so I may as well get that bit out of the way first:
Are Nikon likely to release a DSLR with IS in the next couple of years? I assume not, since they're releasing more VR lenses, but since some of the competition are, I thought they'd have to at some point.
I would like to cover wide angle (10/12mm) upwards. I'd be happy to have a wide fixed, or zoom from 10 - 20mm.
I'm then after a replacement of my Nikkor 18-70 ED kit lens - would anyone suggest alternatives to the expensive Nikkor 17 - 55 f/2.8 G ED, or value Tamron 17-50 2.8? (I'd like the fixed 2.8, although I'm not sure if the IQ is better than the ED kit lens). However, I'd like IS. Ideally, a Nikon body with IS would come out, but if it doesn't, there's currently only the...
Nikkor 18-200MM F3.5-5.6 VR
while this is a great lens if you only carry one lens about (most of the time for me), it would stop me using my old Nikkor 80-200 f2.8 ED, and I don't want that. I'd also prefer a carry about lens with fixed 2.8.
So, to summarise my questions

Will Nikon bring out an IS body?
Is the IQ of the Tamron 17-50 better than the Nikkor kit 18-70 ED?
and the final all in one question:
What lenses should I own
Thanks