For some reason my BWC would not integrate with my MSN Premium account. Anybody got any bright ideas on what's going on?

I had the same problem and I called TMobile and they told me that even though the BWC says that you can (gives you the prompt saying only Hotmail Plus Accounts will work), you can't use your Hotmail account with your blackberry due to Tmobile's lack of an agreement with MSN.

Yeah, got the same response through T-Mobile support.