For those of you like me that have been slavering at the chance to get your hands on CRM5 to see everything they've done with it, CTP3 has been announced! This isn't a public preview yet (we're still months out, there), but it's a start!
When I get a copy, I'll post about some of the best features from a back-end perspective. I'm especially interested in the application isolation they've been touting for a while now. To get a taste of what's been announced so far, hit up this announcement from PDC last year.