I made some contributions on colloquial German starting in 2012, without an account. Now, in January 2013, I've created one because I've become interested in continuing these contributions.
The German dialects and vernacular languages are very diverse, perhaps more so than those of any other European language. Dialects whose places of origin are less than 100 km away from each other, are often not (or hardly) mutually intelligible. However, since World War II, these dialects are successively replaced by regional colloquial varieties of Standard German – a development which is already complete in much of northern and eastern Germany, in full swing in western and central Germany, and more and more affecting also southern Germany and Austria.
The emerging colloquial varieties, although relatively close to Standard German, do still show much regional divergence. Some features, however, are universal (occuring in all colloquials) or widely spread (occuring in a large part of the language area or in a considerable percentage of speakers of several regions). While the more dialectal features cannot always be listed, at least the very common features of colloquial German should be mentioned in a good dictionary. Unfortunately, most existing dictionaries incorporate only the written standard language and the so-called "good usage" of the educated, even though colloquial German is by no means limited to uneducated people, but used by many educated people as well.
I think Wiktionary could really make a difference here.
I'm focusing mostly on grammatical, syntactical and pronunciation differences between colloquial German and the prescriptive standard. For example, colloquial verb forms such as er flechtet instead of er flicht ("he braids (hair)" from flechten) are not even mentioned in most dictionaries, or they are branded "wrong". I wonder how wrong the form can be if a considerable percentage of German-speakers wouldn't even understand the correct flicht.
Not every "grammar mistake" is worth of being mentioned in a dictionary, but those alleged mistakes which are common usage must be mentioned. Unfortunately, prescriptive grammar is still much stronger in Germany and Austria than it is in the English-speaking world.
My mother tongue is German. I was raised in colloquial standard German and learnt the Ripuarian dialect of German when I was a young child. I have more profound foreign language skills in English, Dutch and French. I can also read, but not really use actively, Italian, Spanish, Danish, Norwegian, Swedish, Afrikaans and Arabic. I learnt Latin and Biblical Hebrew in school, but I don't remember too much of them.
My entries will usually be about German and occasionally closely related languages such as Dutch or Luxembourgish.