Last week I wrote about Ubuntu Still Deciding About Intel Acceleration Support. Ubuntu X.Org developers/packagers really want to enable SNA for the Ubuntu 13.04 release since this back-end that's been in development for years now tends to be noticeably faster and more reliable than UXA, the default acceleration method within the current xf86-video-intel DDX driver.
Subsequently, a call for testing was issued of Intel SNA. From Canonical's Timo Aaltonen, "The Ubuntu X team would like people running raring on machines with Intel graphics to try the new acceleration method called 'SNA'. It should have slightly better performance and less bugs than the current default."
Those wishing to help out in testing Intel SNA on Ubuntu should see this Ubuntu.com Wiki page.
Update: There was an issue with the content management system (PHXCMS) causing this article to be made live later than expected. Canonical has ultimately decided they will enable Intel SNA for Ubuntu 13.04. The announcement was made here and the change should happen next week for the xf86-video-intel Ubuntu 13.04 package.