Some time ago I have heard of an attempt to develop an Android app in NetBeans. It sounded a lot like a story of a masochist though. I believe it was done like that. The resources didn't work, there was no support for editing layouts or other XML files. It wasn't a pleasant way to code but some prefered that to switching from their favourite IDE.
Well, I have some good news for NetBeans users - yesterday, on official Oracle blog, there has been posted a Dummy Guide to NetBeans Android Developement. Quickly followed by 5 Step Procedure For an Android Deployment.
The method described on the blog uses a set of plugins called NBAndroid, which have been developed for some time now (the beta label was officialy removed on May 21th in a version 1.7).
As far as I can tell and as is described on NBAndroid blog, currently it supports code completion in XML files, attaching a debbuger at runtime, building singed APKs, some support for test project and more.
While I prefer to do my work in Eclipse, I am curious about the NetBeans implementation and I will defenitely check it out.