I would think you could, couple of things you should figure out first though...
1) do you *really* need 2 burners, burning is more turn-key now than it was just a couple years ago, but buffer under-run is still a real issue to contend with
2) is your system fast enough to keep a steady flow of data to both drives? bus speed, cpu, -->hard drive xfer rates...
3) can your burn software run multiple instances? I don't know of any burn software that will burn 2 at once, it has to be out there somewhere though, industry uses it, but I would suspect what is used in the industry is proprietary and hardware specific.
I'm not an expert in this field, these are just the things that popped into my head when I seen your question. Hope it helps some.