As long as it's there when you install it.
I was fooling around (as usual) and decided to try uninstalling IE using IEradicator. I did download a standalone version of IE 5.5 from evolt.org, and put it in the Internet Explorer folder in Program Files. It's non functional and won't even open, but maybe it satisfies programs that look for it.
Sygate only complained on the first bootup, and now runs normally with no integrated IE in Windows. Even PeoplePC works fine, even though they claim that IE is mandatory.
Interestingly, what did not work after this was AVG 7. It complained that SHFOLDER.DLL was missing and would not run. I downloaded the file and put it in C:\\Windows\\System, after which AVG worked normally. So, if you run AVG and decide to get rid of IE, save SHFOLDER.DLL first.