"It strikes me that the concept of Standard German has a similar problem to the concept of Modern Standard Arabic. It's all very well saying 105 million people speak German as a native language, but that count is just adding up all the speakers of German dialects, many of which are rather different from each other, to the point of unintelligibility in some cases.
The "German language" is a very broad classification, to the extent that if Low German dialects are deemed part of the German language, they to be perfectly honest you could quite reasonably call Dutch a German dialect too."
This guy, who is about the craziest language splitter around, says German is actually 133 different languages (WTF). He is calling a lot of the dialects separate languages.
http://robertlindsay.wordpress.com/2009/03/08/a-reworking-of-german-language-classification/
He goes into the nature of Standard German somewhere in the post, I think maybe around here:
http://robertlindsay.wordpress.com/2009/04/13/a-reworking-of-german-language-classification-part-2-middle-german/
Truth is that Standard German was fixed on the German of Martin Luther around 1550, speaking an Upper Saxon dialect. It gradually became more standardized, but it's still based on an old version, like Standard Italian is based on the Medieval Florentine dialect of Dante. Anyway, since then, Upper Saxon itself has so diverged that Upper Saxon is not even intelligible at ALL with Standard German.
In the same manner, Florentine Italian has diverged so much from the old Standard that is now nearly unintelligible with Standard Italian!
Also, Standard Mandarin was based on the speech of the Beijing suburbs, along with some other stuff mixed in. Anyway, somehow, the Beijing dialect itself (hardcore Hutong speech) is nearly unintelligible with Standard Mandarin! It's like a wild, over the top New York accent on steroids. That same linguist guy talks about that here, where he says that "Chinese" is really 343 languages! Same thing, he is classing a lot of dialects as full languages.
http://robertlindsay.wordpress.com/2008/12/27/a-reworking-of-chinese-language-classification/
Even if you include Low German in "German," Dutch is really Low Franconian as opposed to Low German or Low Saxon, so it gets hard to make a case that Dutch is a German dialect, as it's a tough case to call Low Franconian part of Low German (I would not). On the other hand, CENTRAL Franconian is definitely a part of German all right.
Things get awfully confusing.