MacBook Pro non retina haven't been in the lineup for a while actually. They changed the name to just MacBook Pro, without the retina. Not sure if it was this or last iteration.
The Air will probably not see another update and disappear from the lineup eventually. The thing is they have to lower the Macbook price if they kill the Air. Currently just because of the price the Air probably still sells good.
What they should do is over another thin 15" Macbook and a 17" MacBook Pro and kill the Air and rearrange prices that show that retina is standard in high quality notebooks not some expensive upgrade.
A 17" retina display might have been expensive when they first launched them but now it would just round out the line up and offer something with a decent dGPU. And there really should be a cheaper more mobile 15" thin bezel option for people that don't need a Pro and just want the display size.
Uhm, yes they do.
http://store.apple.com/us/buy-mac/macbook-pro
At far left.
They will lower prices of Macbook before killing off the Macbook Air, just like they have done to the Macbook Pro.