They are saying the beginning of June.
I would say not to expect some huge performance jump.
I mean 667 to 800 fsb, and some extra wireless support, the CPU jumps to 2.4 Ghz, not exactly the 2.0 Ghz mobile CPU they were saying would come with it.
I would say you can cut a deal with vendors right now on existing technology to move inventory out that would probably be worth more than any performance boost you would be paying full retail for in 2 months.