I'd like to know this as well. I know most array languages coupled with a DB aren't as fast as a language with a JIT, but the code is quite expressive. If Kdb+ can ever easily be run on an FPGA or GPU cluster...that would be something.
The FPGAs were used mainly for feedhandlers and there was a different DSL for that (compiling to verilog).
It was indeed rather something to see :)
I've moved into non-finance stuff for quite a while now though, so not sure what's become of it. Given business challenges in that particular sub-field, who knows..