[threeseed]

Samsung/HTC are never going to just abandon Android arguably no matter what Google does.

People have invested money in apps and content which locks them into that platform.

Tizen is a non-starter (nobody is building apps for it). And Microsoft is still struggling for traction.

[castell]

Most new Samsung devices (including all SmartTV and SmartWatch) already use Tizen (based on an evolution of Samsung's Bada). Samsung could switch to Tizen anytime given it features a compatibility layer. People don't buy "Android" devices, they buy by the brand name of the manufacturer e.g. "Samsung".