OS 4.5 and YouTube
 

I haven't been on this forum for a while so if this already been answered than I apologize.

I just found out on another forum that the latest version of OS is 4.5 and you can view YouTube videos on it.

Is that true?

I went to the T-mobile website but the latest version is still 4.2.

Is the 4.5 is the final version? In otherwords, not a beta version?

Thanks for any help.