I guess it depends why you want the articles rewritten. If its for SEO, or to avoid simple detection by copy-detection software (or both!), then there should be plenty to go at.

The state of the art last time I looked was at elsewhere.org - they had a 'post modernist essay generator' that had produced articles which were published by respected academic journals. Complete tosh, but high quality complete tosh!

It's still online, but understand that the article you read has been generated on demand, and will be different to the ones that other people read.

Postmodernist Essay Generator

Maybe it would be possible to modify the Dada Engine to accept blog articles?