Tags and labels going mainstream

Browsing Memeorandum I noticed that everyone was talking about the release of gada.be, which is a meta-search engine with an interesting query mechanism that allows searching and filtering via URL, which is really useful for devices with limited display and keyboard capabilities like mobile phones. For more information you can follow the discussion via Memeorandum or read their about page. I don't know how fresh are their results because a search for gada brings me no results and as any new service they are having some problems with handling requests but I am sure they will fix it fast.

What interests me the most is that they are retrieving tagged results using API calls and giving back resources like this opml list for Web 2.0, so some development towards alternative user interfaces and ranking mechanisms can be build on top of this. I am already expecting an API for the recently launched Google Reader which allows me to label - Google's word for tagging - my subscriptions and each post and know how Yahoo's blog search results evolve, here are the blog results for Web 2.0 which include as expected Flickr and My Web 2.0 results.

With tags and labels going mainstream will them enable the KISS semantic web?