iMichael!, ultimately, it's your money and your decision.
Basing a decision to buy or not buy on a rumor, especially with Apple products, can be an exercise in frustration. Will Apple come out with a retina iPad Mini? Probably, given that all of their other portable devices sport retina displays. But when? That's a tougher question. Maybe this spring. Maybe this fall. Maybe next year. Maybe never.
At the end of the day, the question you should be asking yourself isn't "What doesn't the iPad Mini have right now that I really wish it had?" but "Does the iPad Mini in its current form work for me?"
Some folks want the latest and greatest, so they'll upgrade to the newest iPad or iPhone, even though the updates may be iterative. That's certainly their decision.
Personally, I'm OK with being a generation or two behind. It's not like the iPad 3 stopped working after Apple introduced the iPad 4. And it's not like the iPhone 4 and 4S don't do exactly what they did before their successor models came out.
I came very close to ditching my iPad 3 last year for a Mini. I really like the Mini's size for what I use it for, which is mainly reading and media consumption. But my iPad 3 was working just fine and I'm pretty happy with it. At some point if Apple makes a retina Mini, I'll certainly consider trading in the iPad 3.