Well, I recieved an e-mail back from them this afternoon.
I really should have waited an extra day before worrying. They said that the shipment was lost and that they shipped out another package the next day and gave me an updated shipping number.
That, honestly, would have been nice to know in the first place, but it seems that it's still coming my way after all.
All in all, I'd say OK customer service. Bad for not telling me in the first place, good for getting back to me so quickly.
The new tracking number says the package will be here today, but I'll give it till tomorrow before I start worrying.