If they allowed people to take a single piece of armor, or a single weapon, even if they limited it to legendaries only, they would have to put every single legendary weapon/armor from D1 into D2. Excluding year-1 stuff, that's 20-25ish weapons per type, and 50-60 armor pieces per type, per class. That's in the neighborhood of 1000 items that would have to be in the D2 database, just for cosmetic purposes, so I really don't see that happening.