Unless the 13" rMBP is priced at $1199, I doubt very many 2012 13" MBP purchasers, including myself, will be upset at all.
The 13" MBP sells at either $1199 or $1499 (without any build-to-order extras). I would speculate that Apple could build a 13" MBP that is unchanged except for the Retina display, and the optical drive swapped for battery space, at the same price. And in that case, they would first offer the $1499 model only, and the $1199 model later when more displays are available.