Wikipedia – Use ‘Reading List’ from Web Browser

Of course WikiStats has this (for all languages). :) The top reverted/reverting users are at http://stats.wikimedia.org/EN/EditsRevertsDE.htm#table3 The full rankings should be somewhere in the huge CSV reports archives. https://meta.wikimedia.org/wiki/Wikistats_csv They're updated rarely though and the format is a bit obscure (needs documentation at Meta-Wiki). Still great for digging!

However, as noted, I don't think this is a requirement for anything.

The sheer size of the data is the biggest problem. The XML database dumpfile containing all text of the most recent revisions of the articles is approximately 9.0 GB even when compressed. I haven't seen a EPUB file that big; and in fact, some readers are unable to open a EPUB file larger than a mere 25 MB.

Of course, there are plans to create offline stable versions of Wikipedia, and the Wikipedia:Version 1.0 Editorial Team has been working on this for quite a while. Note that when the team started working, eBooks weren't so widespread as today, so most of their output so far has taken the form of CDs. They might consider eBooks in the near future, but that still remains a possibility.

The next best thing is the recently-introduced Book creater function, allowing you to produce PDF/ODF/openZIM format of manually selected collection of articles.

EDIT: To give you an idea of how large the content of Wikipedia is, take a look at this image. This was back in 2006, when Wikipedia had 4.4 GB of text. Now it's twice that. Typical eBook formats are designed to work with only one small volume of text. If you were to split the contents up into feasible pieces, you're going to end up with hundreds of files. If that's what you want then that's okay, but still, I don't know any existing tool to perform that conversion.