The Mini will be updated approximately when 10.6 is released. There's a reason the MacBook's video chipped innards have been upgraded, all the way down to the white MacBook: Extra video power is needed to run 10.6 reasonably and to take advantage of its ability to off load to the video processor.
I am confused why the white MacBook went Nvidia so far in advance of the Mini. I hope that doesn't mean the Mini's dead.
Still, if the Mini were dead, Apple should let us know so that some percentage of the Mini waiters will give up and go iMac. I'm nearly to the point that I'll have skipped 10.5 entirely; that's a long time for Apple not to have gotten its hand into my wallet. The Mini still sells well as is, apparently, (still
number 5 at Amazon), so perhaps they're not worried about leaving my cash on the table.
This tells me that as long as the Mini runs OS X well enough to sell itself in the Apple store and elsewhere, its tech specs will stay put. Once 10.6 is out, the integrated video Mini will be an obvious performance disaster. I guess.
EDIT: Seriously, check out
the reviews on Amazon for the current Mini from February. They're all insanely positive. It would seem only the hard core Apple fans know it's horribly out of date. Performance wise, it still [surprisingly] impresses. Back to my 10.6 prediction. There's no incentive to update until the OS requires it.