It's very interesting that they've kept around the lower-end 13" cMBP, rather than the higher-end one.
This means one of two things:
1. They have existing stock of the 2.5Ghz and just want to get rid of it.
2. The 2.9Ghz is too powerful relative to the Retina models, and they don't want to encourage people to go with an "outdated" machine where you can still upgrade it down the road.... jeesh, who wants that? Then you won't buy another computer in 2 years.
I guess it's probably the first reason now that I think about it. People like me bought up all the 2.9Ghz models.