A scientist once apologized for being a jerk to me at a meeting the previous year, after research that I presented there was published in a highly-ranked journal. Oddly, I didn't even remember the incident in question, but the change in opinion, apparently just because of the publication venue has stuck with me for a long time.

In the keynote it is asserted that the optical technology will not use blood flow but some other (more direct) measure of neural activity. It sounds to me like a near infrared form of intrinsic imaging. Very intriguing if it works.

Were there any details on what they use if not blood flow?

Assuming that the 1 GB/min figure is because you're saving broadband (back of the envelope math assuming you have two Utah arrays with 32 bits/sample at 30 kHz), you can get enormous space savings with compression. Field potentials are highly correlated across channels, as you no doubt know. Depending on your amplifier you may be able to pack everything into 16 bits/sample too.