It was just a minor bump so they can speed along the painful transition to the Lightning connector ASAP. No one's going to sell their iPad 3rd gen and upgrade.
I am going to upgrade my iPad 3. I mean you can sell it to Amazon for $400, and buy a new one for $500+tax. Doesn't seem like a bad deal to basically lease the iPad 3 for six months for about $120.
I guess, but the new one doesn't seem to have an advantage. At least not one worth the hassle of all that. I'll wait until a noticeable upgrade.