Hotmail/Live Mail In Your Own Domain

MX your domain to hotmail and they do the rest. Pretty cool. However, while having enough spare money to maintain tens of TLD names, I'm too old for relying my ego on a TLD... Still damn cool though. @ddr in your own domain for mail and IM, with full MSN integration. It's way beyond Passport in your own email @ddr. What's the next, spaces.YourDomain.com?