Well, there is no such thing and it looks like there won't be any soon.
However, I was playing around with this GMA500 recently and found some interesting thing.
Looks like Intel recently has released "Intel Embedded Graphics Drivers (IEGD)" pack, dated on 10/23/2009. This is pack intended for developers, but it also contains the latest driver for GMA500 (10.2.0.1447). Sadly, it is XPDM driver (not WDDM) so Vista/7 are not supported (it works, but there are some glitches, also forget about Aero).
I extracted this driver from the pack and uploaded it here:
http://www.niuki.net/GMA500-10.2.0.1447.7z
Please feel free to test.
My experience with using this driver on Win7 (don't have XP to test it):
- MASSIVE 3D performance improvement - 3D Mark 2001 score went from 931 to 1912(!) points. And this is under Software T&L mode (there is no other option available in this driver - at least on Win7).
- DXVA doesn't really work well - artifacts are present.
- Google Earth is much faster, even with 3d building on.
Please note this is unconfigured, generic driver and I am not sure how stable it is. Also, some features might be not available on it. Nevertheless I still believe it is worth to check it. Clearly looks like GMA500 has a very big potential and we just need proper drivers to make the best from it.
I really hope that Intel will release proper WDDM 1.1 (less memory usage, hardware 2D acceleraton) driver soon. This should make Aero finally usable.