The application uses a nice font, its clearly laid out, the table of contents for the articles is handy (as is the drop-down list of suggestions).
But besides a couple esthetic improvements, its still just Wikipedia, and its one more application open that could easily just be another tab in a web browser. Perhaps some more functionality would make it worthwhile (such as wiktionary), or even basic functions like emailing articles would make it worth the memory it uses.
It also seems to crash quite often if you start moving faster than it, or sometimes for no apparent reason - this is something that doesnt seem to have been fixed in the most recent update, so Ill update my review when its fixed.
MattCLane about Wikibot — A Wikipedia Articles Reader, v1.2