Specifically I want to be able to install a parralllel 3.0 Eclipse / MyEclipse environment on this same machine and have the two run completely independently of one another. Is that possible?
Not only is it possible it is the recommended migration path. Run in parallel for awhile then make the swithover at the time that works best for you. There won’t be any problems with it, as long as you don’t try to use the same workbench in both products.