I will not shop in any store that uses this term in its windows or advertising. And if it's a small business, I'll drop in to tell the owner so.
Good luck even finding "Merry Xmas". I know Macy's won't use it and I heard on Tony Snow that Wal-Mart won't say "Merry Christmas".
Does anyone have a list of pro and anti "Merry Christmas" stores so that we can do our Christmas shopping accordingly?