You're right Nedved! FC Bayern's young goaltender Stefan Wessels is German. I did not mention him because he only made three or four appearances for FC Bayern. He started the 1999/2000 season with the FC Bayern youth team (not even FC Bayern B), and was only promoted to the starting spot because of Bayern's top three goaltenders (Oliver Kahn, Bernd Dreher, Sven Scheuer) all were injured.
By the way, I forgot another young German goaltender TSV 1860 München signed goaltender Simon Jentzsch (20) from third division side Karlsruher SC in the off-season. He has made some appearances for the German B national team. But don't expect him to be number 1 goalie for TSV 1860 (Daniel Hoffmann is currently the starting goalie).
Tss, how could you forget Markus Pröll?
He's younger than Wessels & Jentzsch, and was one of the key players in 1.FC Köln's promotion back into the Bundesliga last season, and so also will be the clubs first choice goalie this season. He plays for the german U21 and also was nominated for the german B squad some months ago (where he played the second half in one match I think). He's obviously one of the most promising youngsters at the moment in my opinion.
Here some other youngsters I'd rate as promising, though, I agree, there are quite too few...
Stefan Leitl (22) 1.FC Nürnberg (2nd division)
Markus Kreuz (23) 1.FC Köln
Alexander Voigt (22) 1.FC Köln
Sebastian Schindzielorz (21) VfL Bochum