I don't know about FireWire support, but
NI-DAQmx Base for Mac OS X does support a range of USB and PCI DAQ products and we will continue to add to the number of products supported in the future. We understand that there is a large Mac OS X and Linux community that are very interested in using our products and we will continue to add to the number of products and features that are supported.
My personal suggestions is to keep watching our web site and perhaps setup a few systems with our currently supported products so that you can begin giving us
feedback.
I hope this helps out.
Joshua Prewitt
National Instruments