Apparently NVIDIA made bad chips. And the heat wave over the weekend triggered the failure - I think my room was at around 90º+F when I got back to my apartment, and the laptop was probably hotter than that.
It refused to boot - no chime, dim power light, no display (LCD screen or external). Brought it to the apple store today, expecting a 3-5 day turnaround, the usual. Yay for AppleCare, although it looks like Apple will be repairing this issue for up to 3 years after purchase regardless of coverage status: http://support.apple.com/kb/TS2377