*USB bandwidth is NOT the main issue here as even a cheap USB2 drive should work (say 20MB/second READS for 3D just to be safe).
Again, the issue is the formats that his TV can actually decode via the USB interface and for that he needs to read his TV MANUAL.
**There are also some great solutions such as getting a WDTVLIVE box for about $80 (can add a hard drive). I have been able to use DVDFAB to copy a BluRay movie to ISO format thus keeping all the menus and then play it back on my WDTVLIVEHUB, either on the internal hard drive, USB thumb drive, or by using the WDMYCLOUD.
I'm pretty sure 3D is not supported with this method, nor am I certain of what OTHER solutions can do this aside from BluRay players of course.
Ideally, you want to store your BluRay discs as ISO images and have a method to easily access and play them as given above.