First off, lemme preface this by disclosing that I am a Mac fan of many years (15+). I have 4 Macs networked in the house - only one OSX-capable. I'm not an early adopter, but I will move when I think the kinks are worked out.
Anyway, the problem I have with the new .Mac scheme is that I have nearly all of what they are offering already with my current isp. Webmail, POP mail, hosting, 100MB storage - all for $10/month. I have no use for shared calendaring or synchronization at this point and my backups are happily automated with Retrospect and a CD-RW over my home ethernet.
I am not arguing that some will find .Mac useful. But $100/year? I think a better price point would have been around $40. I just don't think that there will be enough takers at the current pricing for it to be successful. "But that's just my opinion. I could be wrong." :)