Do you remember the leap between Windows Mobile 6 and Windows Mobile 6.5 in features and also the looks? There was nothing I couldn't do with my HD2.
Then they announced Windows Phone 7, developed from scratch, not compatible with old apps etc. It forgot how to sync with Outlook, when connected to PC it acts like Zune player, this all reminded me of the first iPhones, and there was not much you could with them. C'mon, there is no option to remove e-mail account, you can just add them?
For now I'll wait for Windows Mobile Phone Tablet or what they call it version 8 but with SP3.