When do we expect the current, non ret., MBP to be phased out?
When do expect the regular MacBook pro to disappear?
They've been around for 4 years and will be due for a redesign at some point. Since Apple is going thin and retina, it seems inevitable.
I think the only issue is the retinas and sold state drives still cost too much. If they have to sell it for more than $1200, it's an issue.
I'm betting they're gone by this time next year. It could be sooner if the 13" retina display is cheap enough and they can produce the amount they need.