1) [email protected]
2) Used dd for raspbian on Debian wheezy/sid.
3) It's the 4GB class 4 SD that element14 ships. I re-imaged it after downloading and verifying the checksum.
4) Power and SD card, but I first had the issue with a 1TB external HDD (w/ it's own power source) plugged in, and ethernet.
5) Nope, I didn't need to (see below)
I first had this issue, tried unplugging, and replugging the power back in a few times, and still had the solid PWR light (with some weak flickering of the ACT LED). I unplugged everything, and tried again with only the power and SD card. No luck.
I put the SD card in the freezer for a minute or two (I don't know why, I was tipsy), put it back in the Pi, powered it on and still a solid red light. Plugged the ethernet in and the lights came on.
Sorry I can't be more specific, it's Friday night, I've had a few, and I can't get the Pi to do it again.
Potentially important note:
My power setup is in a building with outdated electrical wiring in the USA (meaning, my outlet has no ground prong). From the outlet, there's a 2->3 prong converter connected to a surge protecting power strip, which a generic white power strip connects to, which the AC adaptor connects to, which the Pi connects to. No, it's not safe, but the Pi was working fine with it before. Also, before it had the issue, it was powered down with 'sudo poweroff'.