Montevina is worth waiting for, not because of WiMax, but because it's supposed to be significantly smaller. In addition, intel's "turbo memory" (Actually a small amount of NAND flash memory on an expansion card would be cool, and possible. Most mid and high end PC laptops have an option for it, so it's just a matter of time.
The next update (If they update soon) will put in a multi touch track pad, magnetic lock, and of course the penryn processors.
I wouldn't complain if they went up to the 8700GT, but I just don't think it's going to happen.
I'm pretty sure the TurboCache option has been around since Santa Rosa chipset and Vista launched. I thought the reaction to it was that it didn't end up making sense and Apple and other manufacturers decided to forgo it for the option of using SSDs or Hybrid HDDs.
Also, it's been said many times that the current gpu is the same as the 8700GT.