One of new features of Ubuntu Feisty is that it’s included on universe the xserver-xorg-video-i810-modesetting driver, a replacement for xserver-xorg-video-i810.
With this driver we can reach native device resolutions, without need of 915resolution software.
I have a Dell Latitude with a 915GM video controller. And now i get 1280×800 resolution in my laptop.
Although this package is under development (it’s considered experimental), i have found no problems so far.