I believe that newer versions of the Android OS support this feature natively, so once we get the 2.1 update that should come along for the ride. In the meantime, I believe I have heard of people avoiding the direct sync problem by setting up a program on their computer that would sync their Outlook calendar with their Google calendar, which would then get synced to their phone in the normal way. You can go here:
Getting started with Google Calendar Sync - Google Calendar Help to use Google's own calendar sync app. One drawback is that it only works with the default Google calendar, and cannot be set up to use a different calendar to separate your events if you already use your Google calendar for other things. If you do not use your Google calendar already then this won't be an issue, or if you don't mind them all getting thrown into the same place. I'm pretty sure I've seen other apps that do the same thing but offer more customization, but I can't think of them offhand.
Outlook Calendar syncing-Backflip
