Edit: Ack! Sorry I typed too slow... I posted after a few other posts.
If you use App Brain- can't you uninstall the app from the web?
Rather than do a factory wipe and reset- what about trying booting into recovery and just do a reset from there? I know shutting down the phone sounds like it does the same thing- but I did this once and it helped my problem.
The other suggestion would be if you hold the home button as the phone launched could you get the task manager to come up? If so, then you can click the package tab and uninstall from there.
It's rare that I can't get the Task Manager to interrupt the phone and what it's doing and then either force kill all or uninstall something from there.
Your situation sounds very odd... I switch and try new launchers DAILY. I've had various issues here and there- but I've never had an endless loop with any of them- and I've used some VERY unstable launchers.
For next time, I would recommend having Home Manager installed 1st- it's better than many Home Switching apps as you can force kill ones running in the background from it's interface. It also shows how much memory each OS is running- but regardless, I don't think this would have helped in your case.
I really wouldn't let this dissuade you from using another launcher- If I couldn't use Zeam (my current favorite) or launcher pro, I probably wouldn't stick with Android!