Install Bootcamp Windows7 off external USB optical drive on Lion system
I have a new MBP 17 with my SuperDrive replaced with a hard drive, and with the SuperDrive mounted via USB externally.  I have not been able to install via BootCamp, due to what I understand is some new issue with USB and EFI.  I haven't heard of people having success with rEFit with the latest machines.  The one solution that seems reliable is to open the machine and put the SuperDrive back into the second bay.  The secondary drive can be put into the primary bay for Windows to be installed to it, and then the SuperDrive again removed and the drive with the BootCamp partition moved back to the optical bay.  I can't verify the

Please note, I have yet to do this myself with my machine, though I plan to attempt it as soon as I get a few free hours.