Well. I've heard that it will be 225 quid (sorry Pounds Sterling) in the UK for the basic linux version (512meg memory, 8 gig solid state storage). And that there will be a version with Windows XP, 1 Gig memory and a 120 gig Hard drive (at around 300 quid).
If it goes to usual technical form (1 GBP = 1 USD... Go figure!) you can expect prices similar to the EEE PC.
See Here