Is it a competitor to Android in terms of being able to run n the same hardware? Or is it that it's just another smartphone platform, like 'Droid, Apple, BlackBerry, etc? All I see listed is that it is a phone platform.
It's a Samsung platform, Linux-based. Like Windows 8, many of the services are HTML5-based; the bundled browser is Webkit and actually tops HTML5 test benchmarks among mobile browsers: http://html5test.com/results/mobile.html
I worked with a company that was halfheartedly pitched a couple of demo hardware units last year running Tizen 1.0 for evaluation purposes - they wanted HTML5-based games and apps to bundle with the system or feature prominently on what I assume is an upcoming app store. I wasn't impressed with its broken JS support at the time and didn't look into what it would have taken to rewrite the games to run properly on the platform, but maybe they've come a long way since then?
