Hmmm, two accelerator cards will be daisy chained with pipelining and their performance will magically double. I will believe it when I see it like all other claims made by the OP.
There are some situations where having 2 cards could be beneficial and provide superior hashrates. An example, cubehash on lyra2rev2. The hard part about lyra2rev2 has nothing to do with memory. And, if anyone out there wants to make a FPGA resistant algo, better use a lot of cubehash. It would restrict fpga hashrates, at least temporarily. If lut density doubles or triples again, it would be no problem.