Yes, they are planned to phased out by summer 2010.
There is talk of 20+ more 76 seaters to them too. We will see if that is just an ASA rumor or not. I have not gotten anymore on that one.

The 50's are a dead bird, they are just using them to bridge the gap so to speak. We need a 100 seat jet, and no matter what you think the 76 seat variants will just not to the job management wants them to do. They to are a mid term fix. Lets just hope the C-series performs as published.