ManOfMoss:
I definitely wouldn't take this to mean that a 533 is inherently better than a 733--I'd certainly take a 733 if all other factors were equal. But, if speed isn't terribly important to you and the 533 is cheapter, then it might well be worth it to go that route; it all depends on the prices, your budget, and just how much you really need the extra bit of speed.
In general, that's always an important consideration; the newest, fastest Mac is always the coolest, but a lot of people don't really need it. If the price and all in one form factor of an iMac seems tempting to you, and you don't need massive AltiVec speed (do you run Photoshop a lot or rip massive amounts of MP3s?), then go for the iMac. If you'd like some expansion options but are on a budget, then the G4 466 is a good option (note that in a lot of operations it'll actually be slower than the iMac 600). And, if you've got a few more bucks or you want some expansion options and wouldn't mind the extra punch, then the new 733s really aren't a bad deal (look cooler, too).
In any case, you really can't loose, as long as you don't look back in a few months--then whatever you bought will seem archaic in hindsight. Like a very wise person already said, buy when you feel like you need the upgrade and there's an appealing product. Sure, it's outdated in a few months, but that's always true (though I wouldn't recommend buying a week before a Macworld).
