scott, as of today, there is no DDK1.8 that works with X11. hence we cannot move Ubuntu to 1.8. we are tracking this internally, but it requires engineering effort to make the transition, and there is no good reason and no resources to do it now (except to align ubuntu and android DDK which is not a must have as of today for us).

also the DDK1.7 was especially made to allow a reuse of the kernel driver between Android and Ubuntu (Motorola BIONIC is the reason why this happens...), there is no reason to believe that the DDK1.8 will offer that too...

However, the linaro kernel includes the PVR driver for GB indeed (DDK1.7) but for Ubuntu we use an external PVR module that is provided as an out-of-driver. so you might be able to update the in-tree PVR to 1.8 without impacting Ubuntu images at all.

that said, I believe that GFX in ICS will require much more drivers than just PVR. there are new dss features in the ICS OMAP kernel, as well as new components such as dsscomp or ion which is required for GFX in ICS.

I would definitely recommend that we main a common base kernel used for Ubuntu and put the Android stuff in another branch as I am not sure if the android bits will impact Ubuntu GFX... it might be able to be managed with flags eventually, but let's start with a branch.