Now you might not think this is killer speculation but here's the kicker for Batman Beyond #37 going to a second printing. It's going to Final Order Cutoff for this coming Monday November 11th but apparently retailers won't be able to simply order it from their FOC weekly order lists.
Retailers are going to have to order these pretty much the old fashion way with Diamond. So, as some retailers will likely miss ordering this entirely, some might not even bother if they have to if they have to call in their orders or manually punch in the Diamond Code to search, find and order.
They've also already claimed that orders will be limited and allocations will most likely occur.

The second printing will have an alternate color. This rush to reprint that will cause allocations is to meet the deadline of November 27th that they want to release this additional printing on.
So far we've found no online retailers listing this for pre-sale but will be sure to update once additional information is available or found.
Edit: One of the more reputable and larger comic shops now have this up for pre-order.