I'm working on an internal presentation of what's new in GP 10. We're upgrading to GP 10 internally and I'm working on a training presentation for later this week. The focus is on new stuff that is relevant to our accounting needs, not just a brain dump on new stuff.
For source material I'm using GP's What's New info and the book GP 10 Unleashed from Accolade Publications.
One thing I found that is not relevant to our situation but may be to yours, is the new inventory transfer functionality. Somehow I missed that in previous reviews of GP 10. This fills a big hole in the inventory process by allowing transfers between sites where one site can initiate the transfer and the other site actually accepts the goods.