I think a new iPad Mini with an A6 processor and WITHOUT a Retina Display is a fantastic idea! Retina Display is nice and all, but on the iPad, it needs a lot more battery power and a way more powerful GPU. The iPad Mini can be a tiny bit sluggish at times, so with an A6 and 1GB RAM, this can be a speed machine with even better battery life (a 12 or 13-hour battery life on an iPad Mini could be a sweet thing).
The Retina effect is worth the price, but I honestly don't miss it on the iPad Mini. With games, photos, and video, the iPad Mini screen is perfectly fine. As with web-browsing, I believe Apple should increase the font in Safari to make sharper and easier to read.
I think Apple will take the same direction as it did with the Macbooks. Want a super thin, portable device? Get the iPad Mini. Want a higher quality display and more powerful specs? Get the iPad Retina.
I don't think we'll see an iPad Mini with Retina Display anytime soon, especially if the iPad 5 gets a new design and becomes thinner, lighter, and overall smaller making it closer to the size of the Mini.