If Apple were going to get them back in stock, why would they not take orders? Companies are always happy to take orders, except when they know they won't have the product any longer. This way, customers who want a 5gb iPod will turn to other sources/stores, and deplete those supplies (not that apple doesn't get the money anyway). But it prevents disappointment and administrative hassles.
It simply makes no sense not to take the order, rather than simply say "expected shipping in 3+ weeks" or something.
Sounds like something's up (of course, maybe the 5gb iPod is just getting the touch-sensitive scroll wheel).