Sad day. I've seen 738's showing up in OKC - I am on one next weekend and again in October. First time since moving to OKC in 04 that I can remember flying on a non-MD80 mainline flight.
I always figured OKC would be one of the last markets to see the MD pulled due to short distance (from DFW), so if they are starting to disappear here the overall fleet count must be getting pretty small.