Not too familiar with br iso format let alone 3d.. (dvd is vob and there isn't direct support for that) BUT if the br extension is mts than it can be done currently on these players via the sd card slot if setup correctly. The sd slot is avchd compatable and but they "swapped" that for mvk support on the usb. Besides the obvious size limitations of using sd format you could have lots of fun converting stuff to actually work under the strict panny AVCHD structure and file standards if short cuts are not taken.
Panny does not seem to be willing to do m2ts files at all for me so that puts AVCHDcoder out of the picture (best darn gui setup I found yet btw)..there's one short cut eliminated for ya. stick with mts I would say .
MultiAVCHD will do the proper structuring in a very timely manner if your feeding it suitable framerate/resolution files to begin with (avchd or proper mkv(h.264) files go real fast..remuxed mpeg in mkv container of improper rates is another story that can involve multiAVCHD crashes/lockups).
A Mobiadapter (usb to sd) should be able to be used along with externally powered usb drive to gain suitable storage space. If it requires fat32 only instead of exfat the avchd structuring programs (multiavchd, etc???) will likely do splits to file sizing anyway as such is standard procedure just like on dvd.
I think it pretty much fact that we will not be seeing 3rd party menuing features (found on such programs as multiavchd) due to panny's not being able to be overridden but going the above route of sd card to play br content or mkv-to-mts conversions may offer some other features of a file or of the stock panny menu. For instance under sd AVCHD structure you get audio/video thumbnailing on sd. Do not know as of yet if that is possible with the usb input or how to gain it as it may require avchd support on that part of player or at least structure support there. My structure for my usb could be incorrect to gain that ability. I have seen the nicer thumb previewed navigator menu offered for usb pics along with a 2d/3d tab so I imagine same is capable for usb video content .. Anyone know the answer to this?
BTW, I said "currently" up above on panny usb not supporting avchd on usb BUT it perhaps may indeed be able to be tricked/hijacked into playing more than mkv because I have seen signs that you can force it to think a br is inserted via certain folders (certificate) being included in an avchd structured usb flash drive. Have done it and tricked player into thinking this already but the files in the stream folder were most likely incompatable. It was a matter of picking the wrong avchd format on last step of multiavchd was the route that offered the hijack....Techies have successfully warm booted some toshiba br's by inserting br disk prior to other things so maybe just maybe something can be worked out on these to use usb for other content formats. Wish the goal of getting a br to be a 'do-all' type thing saw the attention of those that hack the game systems all to heck.