1) Blog Archiving Platforms:??
We're currently getting ready for another Canadian federal election, which we're hoping to track electronically at the Infoscape Lab here in Toronto: www.infoscapelab.ca. We're trying to find a good blog archiver that imports/exports complete RSS files with full text entries into a database format that's easily interoperable with MSAccess or Excel (and can be automated). For example, RSS Owl allows people to export single entries into XML, but not aggregated entries for all blogs that mention a candidate like "Stephen Harper" with full text (as far as we know...).
The most difficult question here is, "where are you going to get a list of all blogs mentioning X from?", rather than the technology. Sometimes the hard part really IS the human element :-) If you can produce a list of rss feeds, grabbing them periodically and injecting them into a database is quite straightforward... the tools in that space are pretty sound. [And I'd be happy to dump snips of code at you to do it...] --elijah