count me in on the radio request, would love to be able to play radio through media center
Just to make sure it's clear, you can
play
radio through MC now.
You can play internet radio streams (not what's discussed here) and easily access these through Theater View also. See the connected media view under Audio for examples of these.
For last.fm and Pandora, currently you can only link to the web page for playback through MC. We cannot control the playback using MC's transport controls (play, pause, skip, etc). It is also difficult to use these webpages from Theater View because once you link to them you're looking at the browser page in place of the Theater View screen. You can link to individual stations for either Pandora or last.fm though, so it's somewhat workable. The advanced features mentioned from the original poster are also only available using the webpage's interfaces.
So,
convenient last.fm and Pandora is what MC is not capable of.