It might possibly be because it's going to be free (mostly), with appeal to not only children, casual, and moderate gamers (because the "hardcore" would NEVER stoop so low as to play something with wide appeal, lest they sully their e-peen), but to PARENTS as well.

I've been looking for something to addic...introduce to my daughter by way of non-Barbie entertainment on the PC. Webkinz has been shelved and NeoPets is so poorly done, but I consider even the simplist MMOs to still be out of her reach (she created a new hero in CoH, but I can't let her play it without my direct intervention).

From what I have seen and read, Free Realms seems to be the absolute closest thing to what I've been looking for, and I think that it has a lot of appeal not just with MMO players, but with those who are not yet MMO players...the same way that WoW did it way back when.