I tried to create a RSS feed for multiple tags, sort of working on creating a feed that would give me similar features as the favorite tags rss, but more flexible.
So I created the following tag search: C#+regex or .net+regex or linq* or tfs* or fxcop* or azure. Which works great to retrieve just what I'm after and would allow me to split up the tag search to different feeds if I wanted...
The page even shows a RSS subscribe icon in Chrome, but when clicking it it doesn't bring up any items. It seems either my tag+tag or the tag* option is breaking the RSS subscription, while the page loads just fine.