As part of an ongoing XML/RSS conversation, just delivered an RSS presentation to the campus webmasters group. My piece was on using mt-rssfeed.pl to integrate external RSS feeds into MT-driven sites. Also covered working the db cache path so that mt-rebuild.pl can do its work via cron. Went well.
There sure are a lot of people reinventing the wheel out there, building XML/RSS systems from scratch when there are already a zillion perfectly good tools. I think a lot of the duplicated effort is less a result of need and more a matter of geeks scratching itches. Nothing wrong with that.