On a recent business trip to Milan I visited the Beretta shop there.
I was asking the same question - but please realize they were trying to sell me an ASE 90 (bought a DT-10 here instead). Here is a synopsis of their reply.
The factory had a whole bunch of unfiished 682 receivers lying around and decided to do something with them - dolled them up, fancy wood, etc.
Sell them on the US market as something 'bigger and better' than the 687s - They do have some more bells and whistles.
Notice what a DT-10 cost two years ago versus today (MSRP)- then look at the cost of the new 682 - notice a similarity??
Can you say "marketing?"