I had Unity beta 4.6.0f3 installed. I just downloaded what they are calling “4.6 official release”, and it’s installing “Unity 4.6.0f3”.
Are these two exactly the same version?
Well, if the version hasn’t changed it should be the same, yes. I guess that this version of the beta release performed well enough so they just turned it into a release version. In any case it wouldn’t hurt to redownload the new official installation (just in case they did not change the version or the installer does some things differently).
It was a “release candidate” so, unless serious issues were found, it should be almost identical to what was released.
However, both the installer message and the “Help → About Unity…” menu text still say 4.6.0f3, so who knows what we’ve really got. 
Yes they are the same, as @runevision has stated here:
http://forum.unity3d.com/threads/unity-4-6-0-release-version-4-6-0f3.263342/#post-1863311
PS: I was also downloading the newly released version when I thought i better check first. It’s a pain to download a GB everytime. 