Now this is getting interesting. On my HTC S621 (aka T-Mobile Dash, HTC Excalibur) running Windows Mobile 6, I installed Blackberry Connect client version 4.0. Blackberry Connect has been working great, and today I enabled Microsoft Direct Push (just mail portion, as its db is separate from Blackberry on handheld). And to my surprise it worked fine. It seems like new MDS functionality of Blackberry Connect is working good.