A mate and myself are off to Vienna starting Thursday, going via the Ardennes, the Voges, the Black Forest and the Alps. Coming back similar route but on different roads. Four days to get there, four in Vienna and four back via the KTM factory for a tour (mate has an RC8R).
For a long weekend break (3 to 4 nights) I would go to the Eiffel and Ardennes area at the bottom of Belgium and into Germany. 3.5 to 4 hours from a channel port gets you there (Spa Francorchamps)
I have stayed at this place before,
[size=78%]http://aeaventures.com[/size][/size][size=78%] , [/size]Luxembourg also worth a look.
Check out the RIDE magazine website for some suggested routes.
Good luck