A follow-up to my previous post:
Hooray for some surprisingly classy customer service from the post office! Which, since I'm quick to publicly complain about them when they screw up, I figured deserved some acknowledgement. They sent me a boilerplate "We're sorry, we know you hate not getting your mail" e-mail, which is about what I expected. But the guy in charge of my local PO also called and, since I wasn't home at the time, left a long, informative message on my answering machine explaining exactly what happened and what they were doing about it.
He said he was able to get an image of the address label sent to him -- yay, technology! -- and the address was perfectly correct and legible, so the sender isn't to blame on this one. What happened, apparently, is that the postal clerk at the point of departure entered my zipcode as 78710 rather than 87801, meaning the barcode label on the thing was wrong. Which... is a pretty imaginative typo. Man, that person must have been having a really bad day. I'd be annoyed at them, but, honestly, if I were a postal clerk at this time of the year, I can't help but suspect I might have a few days that bad, myself.
Anyway, I was assured it would make its way to me soon, and sure enough, checking the tracking info now shows it as being here in Socorro, much more quickly than I was expecting. I should presumably have it in the mail tomorrow, which might even mean I can get it where it belongs by Christmas, assuming no more snafus. Yay! And even if it is late, well, the person it's going to used to work for the post office. She totally understands.