I've found a few more rss search tools that I'll be evaluating over the coming days. If you've already had some experience with any of these I'd love to hear about it.
NewsIsFree || dmoz.org weblogs || eatonweb portal || Waypath || BlogStreet || Blawg Search
I'm also looking into searching Google with filetype:rss and searching Daypop with &t=p as suggested by folks in comments.
update: Well, I've given all of the above listed tools a spin and with the one exception of NewsIsFree, none of them were quite right for my purposes (finding the latest blog posts on a particular subject.)
NewsIsFree was the only one to return the kind of results I was after. I've added it to my previous list of three great tools and will be giving it a more serious evaluation in the coming days.
I also put some more time into playing with Google filetype: queries but the lack of date sorting coupled with limited results proved to be more hassle than it was worth.
The daypop "hidden" t=p feed searching was a lot better than Google but cumbersome to use. I created a custom keyword bookmark for it but I'll probably wait for them to provide a real interface before I use it much more.
Expect to hear more from me on this kind of searching and if you've got any tips or tools that you use to find the latest blog posts on a particular topic, please let me know.
