I use a macmini for my development which is used for nothing else but GLbasic and programming and its fine.
When I come to reset up my mac I would personally advise against going the bootcamp method of running windows and go for the Parallels option, simply because unless you are running anything other than GLBasic and maybe a few other "simple" programs, the loss in speed you get running via "emulation" far outweighs the hassles of booting in windows, compiling the code, copying it to a drive both the PC and mac can read and write to, shutting down, booting to mac, compiling, uploading to the iPhone, finding out you missed something out and having to boot back to Windows again. Bootcamp is fast and it does run exactly like Windows should (some might say slow, buggy and crashes a lot lol). But unless you have software that needs every CPU cycle then go for Parallels. You cant really run cpu intensive 3d windows games on the mac mini anyway
I havent tried it but I would imagine that Parallels can run GLBasic fine and be totally useable. Also it removes the need to partition the drive and suddenly realise that 30gb was not really enough for windows and all the graphics, sounds, code and other programs