Since Google just brought out its new reading age analysis tool, I've used it to compare the top thirty sources on Techmeme for a view as to the different reading ages of sources going into the site. I've inclued Techmeme.com itself as a baseline (although Google's reading age tool claims not to have any Techmeme results it does return a score).
Unlike the results for UK newspapers and social networks, these numbers seem to be of only curiosity value really - apart from the fact that Techmeme seems to average a reading age higher than its top contributors, which is odd but meaningless given that Google's reading age tool barely acknowledges that the site is there.
Notes on methodology: the URL in the left-hand column typed into Google Advance Search with the "annotate results with reading levels" option turned on. Different results seem to be generated by icluding the www, in some cases. Results are ordered by % of pages classed "intermediate". HT to Searchengineland for the original pointer that the tool exists.