As Sean and I work on setting up our own aggregator service, we'll be looking around to try to make sure we're not duplicating effort. I'll periodically post notes here regarding other feed aggregation services that authors and readers of this blog might find interesting or useful.
The Digital Arts and Humanities website has several feeds of interest, including its news hub (a feed aggregator), which can be browsed online or syndicated via an RSS 2.0 feed. The site provides mechanisms for thematic browsing of its own internal content as well, and many of these are also available as feeds, for example: Classics and Ancient History as an HTML summary vs. Classics and Ancient History as a feed.
The eclassics ning ring has feeds too (now universally available, yay), including: