Hi Jason!
I've not had an indepth look at the changes to 1.5 but I think there have been over 500 bug fixes/ enhancements and after a discussion with y main web developer, he has warned that this upgrade to 1.5 isn't going to be an easy one. he has been working with the bleeding edge development version and there are a lot of things that have changed, affecting so many plugins.
You can follow progress over at Buddypress Trac:
http://buddypress.trac.wordpress.org/roadmapIt looks like it's literally ready to drop as an official release ANY day though.
I won't be updating for a month or so, until all common plugins get upgraded, but like I say, the upgrade is going to be a pretty complex one this time.
The good news, however is that once the upgrade to 1.5 is done, all future upgrades should be easy.
Let me know what you find out and what you think will happen with S2.
There may well be some cool new things you can achieve! Fingers crossed!

Speak soon,
Ross
