There are a couple of them who can handle blu ray 3D isos already.
Dune has atleast 3 models and the Tizzbird S20t can handle it.
The Windows 8 Netflix app has 5.1 surround capability. I agree that HTPC is the true #1 streaming device, that's why I'm typing this on my HTPC right now.
The latest WD TV live for playing of windows NAS share - plays all files I have ever tried. (the new interface is much less ugly than the old one)
Samsung Smart TV (Quad core model) for streaming (Better picture quality and faster interface than Netflix on Denon DBT3313UD)
For playing local files I have not found anything better than the WD devices.
I hate all the DLNA clients and servers I have tried.