Hmmm you're right, I missed the retina part of the 2010 launch. But the October 11 release was just being pre-installed with iOS 5 and having a white back version. Same chip & RAM as before (previous launch was in September 2010), nothing new & fancy, just a year-old model, running to be 2 years old already.
The last update to the iPod Touch was in October 2011, so that may be the one you're looking for.