How many times have I read, "How do I get the pure Android firmware on to my phone?".
Well, now you can! Two days ago, the Samsung Galaxy S4 Google Special Edition phone went on sale for $649 direct from Google and it has the pure, unadulterated, Android 4.2.2 on it. Unskinned by Samsung. It is the closest you can get to a Nexus firmware on the S4, i9505.
I'm sure that there will be a few of you anxious to try out this firmware on your i9505's and already, dev's are creating ROM packages for this. It's early days yet but here are some that I've found...
DjeMBeY ROM GT-I9505 GOOGLE Special Edition ROM - CWM/TWRP/PhilZ flashable ZIP:
Google Edition galaxy S4 rom for i9505
Galaxy S4 Google Edition Online [I9505GUEUAMFD]
[i9505] Samsung Galaxy S4 Google Edition
I anticipate that there will be more to follow.
However, before rushing off to flash these to your phone... in the words of the old proverb, "Be careful what you wish for!".
The pure Android does not come without its, for some, drawbacks. Gone is the Samsung UI. The camera is perhaps a little basic. Also be prepared to lose some of the standard S4 features such as Smart Stay, Smart Scroll, Motion, Air View, S Voice, etc:
Here are some early reviews of the Samsung Galaxy S4 Google Special Edition...
Samsung Galaxy S4 Google Play Edition Review - Watch CNET's Video Review
Pure Android: Samsung Galaxy S4 and HTC One 'Google Play editions' review | The Verge
AnandTech | HTC One and Samsung Galaxy S 4 Google Play edition Review - Nearly Nexus