Its same or better than iPad 1 and iPad 2.
Which sold millions and no one is complaining.
We still have those models and they are just fine.
Mini will be fine too.
Even if there will be retina mini in fall 2013, the previous mini still be sold. There are still iPhones 3gs being used by millions. Thats the way Apple works. Until Apple, everyone had low resolution and the whole computing world was and still using 1024 displays just fine.
The 3G/3GS was released in 2009/2010. 2-3 years later, Apple introduces a new product line (iPad mini) that uses display tech from 2009/2010 when there's now better display tech available. That's the problem.