As always, the lads over at iFixit were frighteningly quick off the mark with their latest disassembly. Dissection confirmed 512MB of RAM (twice that of the 3GS); a 1GHz ARM Cortex A8 CPU; a 1420mAh Li-Polymer battery (the Nexus One is 1400mAh); and an LCD panel that's glued to the glass and digitizer, meaning if you break the glass, you'll be replacing all three parts.
Speaking of glass, did you know the iPhone's front glass panel is constructed of Corning Gorilla Glass, a chemically strengthened alkali-aluminosilicate thin sheet glass that is reported to be 20 times stiffer and 30 times harder than plastic? The incorporation of Gorilla Glass means it's less prone to wear and tear and, we hope, has added protection against those of us with butter-fingersitis. Other interesting fact: The battery might be absolutely huge but it looks like it'll be fairly easy to replace. iFixit reports that it's just a case of removing two screws and popping the back cover off the phone.
Check out a few pictures below or head on over to iFixit for the full teardown.