"Most importantly, the Duet 2 mic preamps are optimized for any sound source, so no matter what you are recording you’ll capture every detail."
Wow, optimized for any source! What the heck does that mean? Flat, colored, nicely colored, flat with spice, or how about "completely neutral and warm with soul?" Don't laugh, the last one comes from a major manufacturer.
What is optimization anyway, and does this mean that the last Duet had preamps that were optimized for something other than anything? What were the preamps in the last version of Duet optimized for?
A for "a difference you can hear," that tells me that the product will be different, but not necessarily better.
(It's very hard to avoid mentioning the marketing spiel of a beloved microphone manufacturer, here; because the market speak is so similar and ridiculous-though what Apogee is saying is a little less oxymoronic than that from the mic manufacturer.)
I would bet there are changes mostly for the good in the new product, and most people will prefer the new sound. But that doesn't mean that you will. We'll all have to wait for the product.
Personally, I'd like to see them bring back products like the "Mini-Me", which offered more independent operation and much more flexible mating with a wide variety of devices.