so far so good, subscription is now in place, I've upgraded my office install on my system to give it a bit of a spin around the block so to speak to see how it works with some of our macro-heavy excel files, so far it's flawless. Feeling much more confident about the rollover now. After I'm 100% certain the user email data is saved I'll do the MX record changes this friday and everything should be done by next week.
first glance reaction to Office365 is very positive, I like it a lot.