Spring lol.
Even if a Retina mini was ready for spring (same weight/size/battery life <----unlikely) why on earth would Apple release a successor when it can barely meet demand for the current Mini? Sure, by April you'll probably be able to pull one off the shelf in any sku you wish, but Apple will want to milk at least 9 months sales out of the current mini.
I adore my LTE Mini, and a retina version can't come soon enough, I'll be first in line....but spring, seriously? Get real. Oh, and step away from the Digitimes rumours that are endlessly recycled every couple of months. I swear they have a template which they just switch out iPad/iPhone/mac/clock speeds & resolution and replace it with +1 every time. Much of them come true, but only in the sense that saying "it's going to rain" will come true at some point if you say it enough. Hardly prophetic, good grief.