I'll be happy once we see the results of any OpenGL improvements on the Mac. For now, this is all talk.
If Apple really wants gaming to catch on, they should make their games site (apple.com/games) as a tab on the front page. Then at least it would be advertising correctly.
The only "optional" thing I want Apple to do now are ditch the low-end cards (9200 and FX 5200, for examples) and get some mid-level cards for the iMac and 12" PowerBook. I don't mind seeing iBooks, Mac Mini, and eMac with the low-end cards (you seriously shouldn't think about any serious gaming with those machines in the first place), but the iMac and low-end PowerBook are the middle of desktop and laptop lines, so they deserve better.
Anyways, this might be a step in the right direction for gaming. It's quite possible CoreImage and CoreVideo and Quartz are the APIs that'll benefit, however they seem to be quite good as is. Have you tried getting a PC to draw the GUI using the graphics card? Go to nVidia's control panel on a PC, tell it to draw the windows and even make them transparent if you want. It's choppy as hell. Quartz is leaps ahead of that technology. With Longhorn, they might catch up though. Longhorn as Avalon which is Quartz's equal, pretty much. But it requires 64MB of VRAM, more than Quartz Extreme. They haven't shown too many interesting demos with it though.
But, I still think games will be reaping the benefits. It's good news for everyone really.