Based on the description of your needs, I'm not sure the N800 is what you're looking for. I believe you'd almost be happier and better off with an S60 type device like the N95 with QuickOffice, RealPlayer streaming, sync functionality, etc. While Symbian is not Linux, it's still more open than WM, and is desktop Linux friendly using opensync tools. There is surely no actual, reliable sync capability for the N800 at the present time and I'm not sure there ever will be. And like Naranek said, as far as productivity apps go the N800 is still a work in progress as it is not marketed as a productivity device and relies largely on third parties for these types of things. Rather than go on about the reasons for this, I'll defer to what I believe is a very valid point made by Rocketman in a previous thread:

I believe that this is also for the most part due to the fact that independent devs are catering to the majority of consumers who purchased this device for it's intended purpose, which is internet communication and entertainment. Productivity type functionality is coming along, but I'm afraid you may end up waiting longer than you'd like for it.