Extreme,
MyEclipse is based ontop of WTP 1.5, which is part of the Callisto release (a collective term relating to Eclipse 3.2 and 9 other projects). So installing Eclipse 3.2 then MyEclipse 5.0 will be fully compatible.
We are currently wrapping up and getting ready to release MyEclipse 5.0 Miletsone 2 soon which is fully compatible with Eclipse 3.2