Beta is going to be a new application and settings folder so no need to uninstall for that.
Just interested, will it be based on netbeans 7?
We use our own build of the NetBeans platform, currently its set to the 7.0.1 branch, Alpha-4 uses v7, nightly also 7.0.1. But as said, its our own build so you can’t really 100% compare it to the NetBeans IDE versions.