Greetings folks!
Thought I would share my experience with MissingSync's alpha version of MissingSync with WM5 support.
The first two alphas (A6 and A8) did not work for me and I was unable to make an activesync connection to my X51v.
However, the latest alpha (A9) has finally allowed me to sync the contacts / calendar info between my Mac and Axim (via bluetooth). Hooray!!
If this is something you want to try, there are two important steps to remember:
1. Change the computer name (sharing item in prefs) to a name that is less than 21 characters
2. Disable the password on your Axim. This was inhibiting a connection.
Good luck!
- - Jeff