How about using it for HD Video Editing with Final Cut and photoshopping? Oh and also music recording/editing stuff.
Assuming the clock is the same and the software can use all cores available, the next line will be able to do a job faster than on an SP or DP Gainestown based system (4 or 8 core systems respectively). So you end up with 1.5x the core count, and theoretically, it will speed up the same process by that amount.
That said, there's a few things:
1. We don't have much details on Gulftowns yet (available clocks or pricing), and the clocks may not end up the same as what's available now. To meet a price point, they could end up slower. I.e. the base Quad could be 2.4GHz, not 2.66, and some slower clocked variant for the 12 core base system as well. It will certainly have a negative affect, for both single and multi-threaded systems if this ends up the case.
2. MP Gulftown pricing (which is likely to be on the ugly side, assuming they continue with the current pricing strategy used in the '09 models).
3. Exactly how they'll even offer the systems (my guess, is it will be a 6 or 12 core model, no more 4 or 8 core systems).
Details are really scarce ATM on Gulftowns, so it's a hard choice to decide to wait. So it comes back to the old addage you see. If you need a system now, get it. If you can wait, it's up to you to "bet" on whether or not the pricing & overall system value will be worth it. Let the software you're using now determine the choice, as you'd end up wasting money if you dont', as it's much farther behind than the hardware.
Hard choice right now, my gut lends me to think now would be a better time, as either the clocks will get lower, or the pricing will go up (maybe even both). Software will stay the same for awhile, so there's only a few applications worth looking into that many cores.