It. Just. Works.
Just upgraded the guts of my Ubuntu 11.10 desktop to Sandy Bridge: Asus P8Z68-V PRO/GEN3 paired with an i5-2500K and 16GB of G.SKILL DDR3 1866. I’m using an Nvidia card rather than the onboard graphics.
No drivers to install. No fuss. Ubuntu booted without missing a beat. It just works.