Wikipedia over DNS

"Foo over DNS" was innovative and amusing a decade ago. While a clever hack, it has no advantages other than the fact that the latency drops from 200 ms to 20 ms or whatever. I don't know any applications consuming wikipedia blurbs for which that's an issue.

As for parsing Wikipedia and extracting summaries, that's already been done by Freebase. They also let you search, so you don't even need the exact article title. I'm a happy user of their wikipedia blurb feature and a lot of the other data that their API offers. Freebase can be useful for enhancing practically any web app; go check it out if you aren't familiar with it.