I can only speak for myself, not for "Joe User" or the suburban housewife who supposedly makes 90% of household purchasing decisions or the tech-savvy teenager, and I think these specs are pretty poor.
I'm an intermediate Mac user -- when I say "intermediate," I mean that I use my Mac for CD/DVD ripping and burning, file-sharing, Web surfing, e-mail, Civilization III, word processing, photo editing and organization, daily iTunes use (sometimes individually, sometimes simultaneously) -- of nearly four years who had plans to upgrade to a desktop when then G5 appeared in the iMac. I wouldn't even contemplate buying a PC after falling in love with the Mac; but price and specs are nevertheless a major concern.
To think that the new iMac will arrive (based on these likely accurate rumored statistics) with little to no improvement on the G4 iMac, which already features a less-than-stellar video card and insufficient RAM, is a real disappointment. A new form factor, 20th anniversary iMac should do more than meet minimum requirements for all existing apps, especially Apple's own, whether they're intended for pro users or not. Who would feel comfortable about buying a new, out-of-the-box computer that is already behind the times in terms of hardware (FireWire 800) and software (Motion)? I want something that will stay useable for slightly longer than my G3/500 iBook has, and this proposed G5 iMac certainly won't.
I agree with the person who said he buys his computer for tomorrow, not just today. If prices were lower, that mentality might change; but there's even talk that these will be raised.
Last week I was really excited for the new iMac. That has since changed.