3d Warehouse is one of the first products or sites from Google I'm aware of that is actually calling Tags tags. Try the following search:

http://sketchup.google.com/3dwarehouse/search?tags=skyscraper

your rss feed isn't generous at ALL!!!

http://www.cybersome.com/xna/

i wonder if there will be plans for a StechUp API!?!

... the new 3D Warehouse site (which, surprisingly enough, has no Beta sign) ...
It might not have a beta sign, but it is still in beta:

   An important caveat before you rush off to try it out: the 3D Warehouse is still in beta. This means that we think it's cool enough for you to use, but we know it's not perfect yet. We want you to explore it, use it, have fun with it, but please don't send us dog poop in the mail if things don't always work exactly the way they should. Let us know what happened, and we'll do our best to fix it. Promise.
(from http://www.sketchup.com/index.php?id=1439)

Typical launch day syndrome – I'm getting errors when I want to share my 3D model. Upload unsuccessful, JavaScript errors etc.

I think it is realy cool everyone i know uses it and i think new fetures should be added