It's not going to be more useful to a Java developer than Eclipse is currently, but that's because we're going after a very different end goal. FWIW, all our work is done in LT and it is far more efficient than I used to be with Vim.
Is there a screencast where I can see you being more efficient in LT than Vim?
I (clojure hobbyist) play around with it regularly but IMHO it's not really ready for prime time yet.