Just to clarify, I don't think R&C will challenge Mario Galaxy's lifetime figures, but after its first full week on release I think it will be performing about as well as Galaxy.
People shouldn't dismiss R&C's popularity in Japan. R&C4 did over 85,000 in its first week and 222,000 lifetime (according to this site).
I predict Galaxy will be under 100,000 in its second week, so I think the new R&C game could challenge those figures.
PSN - hanafuda







