Yes. I think the prosumer market for Apple is bigger than a lot of people think. Creative professionals, artists, hobbyists, etc. - people who aren't going to be editing Miami Vice, but who need more than what an iMac offers (or don't like the idea of paying for an LCD screen they can't reuse - irrelevant as prices drop, but real for now). (And, honestly, I see no reason to own a Mac Mini unless it's running your home entertainment system or something.)
These are the type of people buying the low-end MacBook Pros and black Macbooks - they don't need the bells and whistles of a 17", but they don't really want the white MB (whether for genuine reasons or ego) - and they were a huge, huge, huge part of the G4 and G5 tower market.
(Yes, the new Quads are the same price and a better value than the G5 towers were - but computer prices trend down over time, hobbyists/prosumers don't expect to pay that much or put up with a tower that large for their needs.)
So we're talking Core 2 based, smaller tower form factor, two hard drive bays, a games-capable GPU stock (hey, we want switchers and Bootcampers, right?), four RAM slots (not the FB ECC heatsinked stuff on the Mac Pros - I want to fill it with 4GB and not pay $850) and however many PCI/PCI-E/PCI-X (whatever the current standard is, it escapes my mind) slots you get with a normal mid-tower.
Basically, an Apple version of the mainstream desktop line, priced in line with Apple products - I'm not asking for a $999-1299 deal. $1500-2000 is enough. And that top end leads people to the Xeons, for not a whole lot more.