The Undroid is a plug-in for NetBeans which allows you to work on Android applications using the NetBeans IDE. You can find more info from the Undroid Project Website.
I've been waiting for something like this for quite some time now. Actually, I've been waiting since the Android SDK was released to the public.
Quite frankly, I hate jumping between IDEs while working on different projects and if possible would like to have everything in one neat package. This is definitely one more step in the right direction.