Th e only store that ever asked me about my age was Target, just recently with Geist. The guy asked me for my birthday, discovered, after much thought, that I was too young, and then proceeded to scan the item and print the receipt.
I've never been stopped from buying mature games (all three of them!), so as long as Nintendo offered another, not mature rated bundle along side of the RE4 bundle, I think it'd be a rad idea. They should have done it earlier, but perhaps it could be done along side the PS2 release, although I don't think it'd have that great an effect....but it'd be better than nothing.