Anson,
We'd love to have it out by the end of the month. I can't make any guarantees on that though. There's a few minor issues we're investigating right now that affect current features, so those take priority. Additionally, (as you mention) 2.5 is out now, so if any issues crop up there, they will definitely have priority.
Regarding 2.5, we've tested JFBConnect v4.1.1 with the betas and the RC1 releases for that Joomla version. We are putting JFBConnect through the paces with the final release as well, and things look good. Like with any upgrade, we'd recommend creating a backup of your site first and testing on a development site before going live. With that said, we do believe JFBConnect is Joomla 2.5 ready, and we plan to fully support any issues that are reported due to conflicts.
Hope that helps,
Alex