24-32 months of planning, developing, and programming just for 6-12 newcomers? :-(
I guess it depends on who are those newcomers...
It's a given that we aren't getting a lot of newcomers, Sakurai has warned us of such for a long time. Having 3 reveals at E3, as opposed to Melee's 4 and Brawl's 5, is a testament to that.
Even then it's probably for the best. There aren't a lot of Nintendo All-Stars left, I personally have trouble making a roster of 50 characters where I feel that all characters are deserving and worthwhile. Plus, as Sakurai himself has said, there's a certain charm to games with a big cast of characters, but they tend to be very unbalanced. Just looking at how unbalanced Brawl is, imagine a cast of 50 characters who aren't polished the least. As a result of having less newcomers, more attention can be given to each newcomer to make them very unique and balanced, and we're even seeing quite some balancing for many of the veterans who were left behind in Brawl (Samus, DK, Link, etc).
In the end, it's for the best that we're probably getting somewhere in the 8-12 range (I don't think anything under 8 is plausible).