I have a MBP and both the BB Curve 8310 & BB 8820. Currently I am using VMware Fusion to run Windows XP and the BlackBerry Desktop Manager, but you can go the native MAC route as well
BlackBerry is providing PocketMac for BlackBerry for FREE, goto
www.pocketmac.net and click on the BlackBerry sync app. You will have to confirm some BB info.
You can also go with the MissingSync from MarkSpace
www.markspace.com. I have used their apps with the WinMobile side and they work pretty well. The issue I am reading right now in their forums is some are having issues and some are not. Its only release 1.03 so I would wait and see if you can before jumping. You can run PocketMac for FREE so give it a try.
Remember you will need the .alx file to install it on the BB device since the MAC does not like to install .exe even with File Juicer you may or may not get the .alx files to unpack.