Activesync isn't as thorough as a BES server. Some of the features depend on the phone, version of activesync, etc. AS is trying to replicate much of the BES feature set. Most AS implementations have at least some basic functionality to force a password or lock your device remotely. You can do other things like disable bluetooth, disallow certain apps, etc. You can see a lost of some of the policy options here: http://technet.microsoft.com/en-us/l.../bb123484.aspx

The only way to sync with a corporate server and not give control of your phone, is to use a standard mail protocol like POP3 or IMAP (similar to BIS). Unfortunately, doing so limits your ability to use other features such as calendaring, address-book lookup, etc.