All of last years models are moved to the refurb store where they sell them for about 22% off (15% off for refurb and another 7 for being the previous years model). You will never find a previous model for sale in apple's normal store.
Apple will either come with a smaller Ivy Bridge dual core mini with HD4000 and SSD at the same price, or at 499 if it still has a HD.
Apple will merge it with the pro, make the whole a little larger, come with a high Ghz quad core i7 and discrete graphics, but then the price will go to 999 or higher.
They make both models above.
And all of this NOT before 2013. They are busy with iPhones and iMacs till the end of the year.