As much as I'd like to believe the rumor sites, and despite how dead on they've seemed to be lately, I wonder if Apple would have put in all the work updating the 13" if they knew they were going to introduce a retina model a mere four months later.
Then again, they may do like they did the 15" model, and release them side by side.
A good way to figure out a price would be to configure a 13" current model with 8 gigs and a 256gb ssd and deduct $100 or $200 from that, as they did with the 15".* By that reasoning, the price would be $1600 to $1700.
*So that way, they and all the reviewers can say, "Hey, it's pricey, but it's still cheaper than a similarly spec'ed classic model!"
Apple likes to refresh lines incrementally. They already refreshed the macbook line. We should see an iPhone refresh this fall, then iPad in spring, then Macbook next summer.