Seeing as this went out in an email, Apple approved of this. That tells me that they're incredibly responsive to their quarterly earning reports where sales fell 22%, and are trying to see how much they need to discount the next generation model to get product sales where they want it.
Exactly. The 13" rMBP was the only "new" MacBook available for the holidays, and my guess is that while they knew it wouldn't be a volume seller, they were hoping for higher sales than what they got. I think $1499 for the base 13" and $1699 for the 256GB version would be "sweet spots," though that would break with Apple's typical price differential for NAND (their margins are as high as the manufacturer's, or even higher). I think we'll see a significant change to the rMBP price structure with the 2013 models, perhaps similar to what we saw for the late-2010 MacBook Air.