Norm Koren at
http://www.normankoren.comhas a section on the Epson 2450, which he has been using for medium format scanning, and he is gradually adding new information on the 3200 from Europe where it was released earlier, and which he will likely buy and review soon, now that it is available in the USA.
He quotes early reports suggesting that the 3200 might not be much sharper, but is definitely faster, so perhaps some of his comments on the 2450 are a rough guide:
"[the Epson 2450 is] adequate for 8½x11 inch prints from 35mm ... [and] is excellent for medium format prints up to 13x19 inches."
"Sharpness is equivalent to about a 1600 dpi dedicated film scanner"
"Color quality is excellent"