I've been playing around with a wikipedia layer on Google Maps - http://retred.org - code here: https://github.com/twistedvisions/anaximander. It's just a couple weekends play at the moment, but the cool thing about it is the date slider at the top - you can see what was going on in a certain area at a certain time.
It's a bit shit at the moment (and only has 10% of dbpedia's births, deaths, city foundations and battles at the moment - things with both a time and a place) , but have a play and try not to break my AWS micro instance!
V interesting. I've been looking at this too. There were a few deficiencies in the google implementation that bugged me. (1) You have to click on icons to read the info, I think the wikipedia layer should be browsable and ideally include photos. (2) No way to filter to certain articles (e.g. WWII battles) and (3) No date filter - as you've spotted. Tweet me @mbrenig if you want to talk more.
It's a bit shit at the moment (and only has 10% of dbpedia's births, deaths, city foundations and battles at the moment - things with both a time and a place) , but have a play and try not to break my AWS micro instance!