Intel only. Looks like I'll be sticking with Stainless (http://www.stainlessapp.com/) -- probably would've stuck with it anyway, it's a pretty nifty little Mac browser.
V8 was i386-only for a long time, it's had x86_64 and ARM support for maybe 6 months. Android originally used Webkit's Squirrelfish, I think the Palm Pre shipped with V8 before Android did!
