There's not a lot in it for the consumer. Surprise!
For Samsung, however, moving away from Android likely gets them out of an expensive and pointless proxy war with Apple. That's a big deal for Samsung.
Apple's Android vendetta has been about Holy Vengeance Upon Google from the beginning, not really about Samsung. If Samsung could gain a platform that they won't be sued over for including basic functions, Samsung could get back to the business of making smartphones, rather than being a professional defendant.
Making smartphones is actually something Samsung does phenomenally well. Also, Tizen is targeted at other gadgets (read: tablets and smart TVs), other areas of Samsung strength.
The downside for Samsung is that Tizen does not yet have an app-building community like iOS or Android, and it would take years to build one. This looks like Samsung testing waters to me.