This is one of those things that I'm embarrassed to say that I honestly just discovered. I guess I hadn't really needed to turn a search result into an RSS feed until recently, but when I did, I was actually stumped for a bit as to the best way to go about doing so. I mean, I'm familiar with "Alerts," but a feed? Hmmm... Well, as it turns out, you can do this with Live Search!
According to this blog post from 2005, (yeah 2005...I told you this was embarrassing) you can turn any web search into a feed. I really didn't know this!
The trick is to do a search, then append the text ‘&format=rss’ to the URL. Subscribe. I'm only admitting my ignorance here in case someone else, like me, finds this useful.