Just an FYI, I formatted my thumb drive to NTFS and did the same thing with similar results.
I couldn't play the file from the thumb drive, however I was able to copy the file over to my phone and play it from there with no problems.
It looks like it's probably read-only access for NTFS.
Well, I'd be almost OK with read-only access, but read-only in the sense that it could read off the flash card and play it directly.
Keep in mind i'm running custom rom (AOKP) and custom kernel (franco kernel) but this should at least show it's possible with the nexus 7 once developers get their hands on it. Might even be enabled by default in Jelly Bean.
Yeah, NTFS support seems to be popular enough to be built into custom ROMs. However, (some?) Asus devices can do both NTFS and exFAT natively because they licenced the drivers from
Tuxera.
BTW, I know NTFS support is not built into non-adulterated Ice Cream Sandwich, so my guess is that it's not built into non-adulterated Jelly Bean either, but who knows.
Here's hoping for an 8" Asus tablet with SD.