Tizen OS, has gotten its hands on the SDK and released some screenshots to prove it. If legit, they reveal a basic UI that seems to be inspired by a range of other OSs -- in addition to Tizen's progenitor, MeeGo -- while also managing to look a bit uninspired. It's hard to know whether the absence of frills like widgets is due to this being an early build, or whether it's because Tizen is intended as a lower-end OS, but either way it's too early to make any harsh judgement. Curiously, the user-agent used to grab the screenshots is listed as a "Samsung GT-I9500," which at the very least reminds us that there's a Tizen-running Sammyphone somewhere on the horizon. In fact, this could even become Bada 3.0.
Update: It turns out the screenshots are indeed legit and come from a "very early preview" of the Tizen OS that is now openly available -- see more coverage at the CNXSoft link below.