US15W will not support Aero features so providing an XPDM driver is a better investment for Intel as we can cover a wider range of O/S with one driver (XP and Vista are covered by one driver development and testing).
WHQL is not important for embedded applications (it is not required for embedded use cases to be Windows Certified) so Intel can put the appropriate resources into driver development and other product development rather than paying Microsoft for WHQL for applications that do not need it. You can turn off the WHQL error in your configuration.
Windows 7 is not yet "plan of record" for IEGD so that should not work.
10.2, according to our testing, improved general over-all stability and perfromance. The addition of new features (such as compositing) puts new strains on the limited resources of the US15W chipset (i.e. memory) so you either have not set the graphics aperature to the maximum 256MB, or are putting too much content into the limited memeory thus causing the issues you see (something the driver cannot control).
Most customers are very happy with the improvements in the 10.2 release.
If you have a Premier Support account, you can enter specific issues that you see (including details on how to reproduce) and we will be able to attept to root-cause the issues.
i can confirm (for Linux) that 10.2 improved performance over 10.1 driver package in terms of CPU usage while playing a DVD.
Im running the 10.2 driver now under SuSE 11.0 (X.org 1.4) and I get CPU usage around 20\% for the mplayer when decoding MPEG2. Also rendering looks better although I still see the X server also consuming some 25\%to 30\% of CPU load on fullscreen mode, but I guess I might have a DRI configuration issue somewhere.