The final version 0.7 of the Eclipse WebTools Platform (WTP) was released a few days ago. I’ve been using the recent milestone releases for a few months now, and they’ve already been very stable and functional. If you’re using Eclipse 3.1 or planning on upgrading to 3.1, I highly recommend that you install WTP as well.
If you’re installing 3.1 from scratch, you may want to grab one of the All-in-one packages that include Eclipse 3.1, WTP, and all prerequisites.
Now that the WTP release is final, it would be cool if the Ruby on Rails guys would build an RST release on top of that, as WTP was conceived as a generic platform with JST being only one implementation. With RubyEclipse there’s already a basic Ruby plugin for Eclipse, but it’s rather limited and development seems to have stalled. Taking this to the next level and adding Rails support at that opportunity would be awesome.