It makes it incredibly easy to create an rpm/deb/etc. from a directory, rpm, npm, gem, python module, etc.
Here's a BayLISA video about it: http://vimeo.com/23940598
So it should be a little more straightforward. Of course, when yoiu roll your own package, you don't get automatic security updates, so that's still a pain.
dosen't seem to be available in debian stable, but i see it in my ubuntu 10.04.
last time i used it i needed to modify (couple of lines) to accommodate file name used by modern java versions. it works well as far as i can tell.
openjdk is a far more sustainable solution but we needed sun java for some proprietary crap that refused to run on java or tomcat from the repos.