The OSS emulation layer gives 2 channels, I
think.
Actually, using Audacity/OSS with OSS emulation over ALSA we've
recorded with 8 inputs and 2 outputs using a Delta 1010. (Audacity
doesn't support more than 2 outputs in version 1.1.3, but it does
support up to 16 inputs in theory.)
Cheers
Daniel