I feel like we're being abandoned:
http://support.apple.com/kb/TS3977
Apple sounds to have disavowed responsibility by putting the onus on the manufacturer of third party devices / software.
Now I don't know how DisplayLink drivers do their magic, but is it possible to move some of the more broken features off of kernel space as a stop gap until Apple decides to support DL again?
E.g. MacFuse is a userspace filesystem, and moves the responsibility of talking to mounted devices away from kernelspace while sacrificing some speed -- at this point, speed of DL displays is a non-issue if it won't even work.