I inadvertently blogged about this new CS2008.5 SP1 feature last week after encountering an error using the post editor's Insert Media selector. As I described in that post, the fix was adding theme.config information to support the new media handling properties.
This function should probably fall in the category of "it's the small things...", but it can be very useful in managing the display of images on your community site. There's a lot of intelligence behind the scenes in image handling here, so it's a real time saver if you need to reproduce it on your site from scratch. I'm able to use this right away for one of my clients who was asking for it. That guy is such a lucky spud!
Regarding the Community Server 2008.5 SP1 update list which I mentioned that I hadn't yet seen, I stumbled on CS2008.5 SP1 Release Notes.txt in the CS2008.5 SP1 Update download. Dang stuff's always in the last place you look! I thought I'd post it for those interested in CS2008.5 SP1 Enhancements and Bug Fixes.