WDTV’s are “Hardware” decoders … 10Bit / Hi10p requires “Software” decoding (a min Quad-Core for 1080p & most probably, gigs of RAM)
so, the answer is “no” it’s not possible on any current WDTV.
P.S. the same applies to H.265 requires a lot of processing power which the the WDTV doesent have.
Here’s the specs of the WDTV Live Streaming… to put everything into perspective
Sigma Designs SMP8670AD 700 MHz processor with 512MB of DDR2 memory from Nanya