I'm thinking of picking up a Wasabi 360 because... well I'm getting tired of burning backups. I'm just wondering though, instead of buying a brand new HDD, can I use a drive that already has a Windows partition on it? I'm a student and have a 2TB external eSATA drive that I boot off of when I'm at school. If I could set aside 1TB or so and dedicate it to my backups, that would save me a bit of money.

Anyone know?

try asking on their forum. probably get better help there.

I don't know about the Wasabi, but I've installed the XKey on both the pphat and the slim and it works great.
They will also be releasing an addon that will allow you to rip iso's directly from the 360 (release date Jan-Feb).
It also looks like many of the major supplies have given up on the Wasabi as the release date started in Oct and they still have not released yet, and there are reported FW issues that they are addressing in the beta initial release.
Price is the same and avaiable now.
They have been very dilligent in releasing FW updates (up to 1.12 now).
It can take any USB 2.0 HDD up to 2TB and only cares that you have a directory called "games" where you store the iso
My opinion only