Not sure why I hadn't read about something like this before.
For many products, Apple keeps around last years model as a cheaper option. iPhone 4/4S, iPad 2 is still for sale, even the last iPod touch.
Makes total sense they'll do the same with the iPad mini.
And for all of them, Apple keeps the price the same for the new device and the older models start at $100 cheaper than the newer model. $229 seems low for the current iPad mini...I'd guess $249 with the updated retina one keeping the same $329 starting price.