Actually Pinot Noir has been grown in Germany for centuries. I think it was brought over from Burgundy by the Cistercians. Recently, however, there's been a proliferation in very good quality examples.

I was going to hold this fact for a quiz, but this is the right time to use it. Germany is the world's #3 producer of Pinot Noir. Yes, you read that right. It goes France, USA, and then Germany. Many Americans would probably also be shocked to hear, that despite what we see in the German aisles of our wine shops, that German wine production is getting close to a 50-50 red-white split.

Assmannhausen at the western end of the Rheingau has been making great PN for centuries. However, PN also dominates way up north in Ahr. With global warming we're seeing the Pinot Trinity (PN, PB & PG) taking off in Baden and now the Pfalz.

I did a little research to match up the wines you mention to regions since I'm a mere mortal and don't yet know all the German vineyard names:
rudolf furst 2005 centgrafenberg - FRANCONIA (FRANKEN)
bernard huber 2006 heckler schlossberg - BADEN
krone assmannhausen 2006 assmannshauser hollenberg - RHEINGAU
meyer-nakel 2007 blaschiefer - AHR
okonomierat rebholz 2003 sonnwnschein siebeldingen - PFALZ
von schonborn 2007 assmannshauser hollenberg - RHEINGAU

Few of these wines make it to the US. That's partly because the German market is thirsty for red wines and partly because our conception of German wines is still white (and too often sweet) and that is what gets imported here in droves. However, many of these reds would probably be a bit shocking to California Pinot Noir lovers because of their delicate, austere nature. It's a topic that DeGrandCru and I got into on this other topic:
http://www.snooth.com/talk/#http://www.snooth.com/talk/topic/a-matter-of-taste/