I've been a Windows mobile user for quite some time now and am extremely excited about my new Pre. I was worried at first it might not work, but it works like a charm with my mobile sync service: interways.net
Just click on Products and then interWaysMAIL. There is a special section for Palm Pre.
They offer perfect sync, really fast, and very inexpensive. Sync works great with my Mac and Windows machines, everything is in sync and I'm happy.