Honestly, I'd just try it. A fellow in SF states that foodstores are accepting the 64t stocks. It is my understanding that WalMart will handle the new film. I'd just drop a test cart in an envelope and write "Super 8 movie film" on it. I don't really think it matters what you write on the bag. One time I wrote "K-14" on a spool of VNF film and it came back as a "Sorry, can't process k14". So where ever the bags do go, someone who knows a bit about it looks it over. If you askfor something the lab can't do, I believe the worst that would happen is that it will get sent back.
I wouldn't bother to ask the people who work there. Yesterday I asked them if they processed slide film. The responce was "Process it into what?" They may not be the evil empire, but their training progam leaves alot to be desired.