Conversation so far:
What were some of CBC Radio 3's webcasts?
CBC Radio 3 's webcasets were Sessions
When did CBC Radio 3's use of Icecast start?
From 2005 the Icecast stream was available from CBC Radio 3's website
When did CBC Radio 3's use of Icecast end?
CBC Radio 3's use of Icecast ended in 2009.

Question: Why did it end?
Self-contained rewrite: Why did CBC Radio 3's use of Icecast end?