I've noticed this too. I'm late to Carcassonne and was trying to buy the exp. in order. I can't seem to find mention of why it's out of stock. The latest reprint seemed to be in 2013 (if I'm reading BGG correctly). Even on the Z-Man site it's out of stock, it'd be nice if they posted a little more information.
It seems like a gap in printing vs. demand rather than an out of print.
I saw a new old stock copy on the shelf for $18 at a LGS after I got my pieces of evilbay.
They seem to be around, just not many copies.
Hopefully another run soon.