Yesterday I extracted all the pages from German and English Wikipedia that contain math.
Here are the results
The archive contains all relevant pages in portions of 1000 pages file. The files fit to the default format for MediaWiki dumps, so that they can be imported via importDump.php. (I only tested a few of them. So if you find errors don't hesitate to contact me.)
For the creation of the files I used the following python script: