Here is a Video made by Yuya Adachi showing some of his work of porting the Tizen OS (latest version 2.1b build at the time of this post) onto the Samsung Galaxy S2 (GT-9100).

He demonstrates:

• Notification bar access to display brightness
• Unlock Screen
• Settings, Basic application navigation
• Calendar
• Dialer Access

 
It will be interesting to see how this project evolves.