Yes well, in theory it is just like any other UI is. Nucleus is the OS used by Samsung on all their dumbphones. Bada is developed specifically to run on that OS because Samsung want a light weight smartphone os o run on less expensive hardware.

Bada platform has some open source (open bsd or free bsd) components, but that's it as far as open source is concerned.

Read about Bada on the official Bada servers for info and sdk and everything. Then you will see the wikipage is speculative at best.