I'm posting a copy of this here, in hopes of reaching as many as possible...
If you need to order z/OS V1R13 (5694-A01), it is recommended to have your order submitted by January 17, 2014. Ordering will be withdrawn for z/OS V1R13 (5694-A01) on January 31, 2014.
I'm directing this comment to those still on z/OS V1R11 and not yet ordered z/OS V1R13. That is because z/OS R11 is only coexistence-supported up to R13, as we've discussed on this forum.
I know all good SHARE folks are already off of z/OS R11, though :)