I noticed a few changes a number of weeks ago. I'm mainly a fan of the preset stations in the Jazz, Classical, Electronica and Top40 streams. Some have simply moved around to other stream "folders" but today I can't get a bleeping thing from any of the streams. Yikes. I'm addicted it seems to my iTunes radio.
I just remembered that I had saved the actual KoS URL (not a Live365 link) somewhere else as text, and also as a separate web radio link in a personal playlist folder in iTunes... and I'm listening now.