I don't see any updates available via http://wowza.com/wowzaide2 (just checked in Eclipse)
For anyone looking to dev against the 4.x Wowza Engine, you'll need to make a few small edits to your Debug / Run Configurations.
VM arguments just need a quick edit:
You'll also need to re-add all your libraries to your classpath.
I've also just run through the process in my Windows setup too - and just make sure you edit your paths accordingly.
Feel free to bug me if you want more info.
Edit - not 100% working yet - I'll post back.