I know everyone is very upset about windows users not being able to do the install (me too)....but today I installed Firecore very easily using GreenPois0n all using my windows XP system.
I simply downloaded the latest release RC6.1 of Greenpois0n for Windows, ran the exe file, clicked "yes" at the prompt asking if I was jailbreakin ATV2, then followed the instructions on the screen.
Once it was completed, I reconnected the ATV2 to the TV and clicked on the new option showing "inject software", and it installed NitoTV and completed the jailbreak process.
Then I downloaded the latest ATV2Black Firecore software install package for Windows from my download section and followed the onscreen instructions.
Everything worked flawless and I have it all working fine.
The wait is over!!!!! and hopefullly some of the complaining happening on this forum too.