@Rickroller, it's full push, as opposed to 5 minute polling or whatever. Coming from BB, it's good to have true push back that isn't GMail, as I hate GMails app, interface, and just in general. If I had known when I got my first Android device that I could've linked my hotmail email to Googles stuff instead of creating a GMail, I definitely would've.
@danwill I believe that's what I did, is it Email.apk and looks like Vanilla Android?
Found another fix, if you download the 2.2 Stock Email app (just google 2.2 Email.apk) it's the Vanilla Android email app and will work fine (which is why it worked on my Milestone, as it had Vanilla 2.1). Works great, and doesn't have that stupid Exchange 2010 issue, AND you don't have to pay for it like TouchDown.
Just to let others know that read this thread, the issue has something to do with Exchange 2010 demanding password / PIN protection on devices. The Vanilla Android app was somehow programmed to circumvent this security feature (probably for things like Hotmail and whatnot that have Exchange but don't demand such high security features) but HTCs was not.
To be completely honest, the stock Email applications Delete / Reply All buttons being along the bottom are much easier than the Mails Menu > Delete system. The only big thing is the icon doesn't match, but I skin my apps to look like Vanilla 2.0 Android icons anyways, so it fits right in.