Sweet, just checked over at XDA and someone has it for download, grabbing now....
Edit for anyone that wants it:
http://android.clients.google.com/p...H-L720_MDL_CSB_user_RP_to_MF9_CSB_user_RP.zip
Put it onto your SD card and rename it to update.zip (renaming the file isn't required as someone found)
Then boot into recovery. When the phone is powered off, hold down vol+, home, and power and keep holding them down. The phone boots up and you'll see the galaxy s4 logo and in small text at the top it says booting into recovery. Then let go of the power button but keep holding down vol+ and home until you get to a recovery menu. Use the vol keys to scroll through the options and the power button to chose an option. You should see an option for update via external storage and then chose the zip file.
This way you dont have to wait for it to push to your phone OTA. Also, these steps are for stock, non-rooted, Sprint gs4 phones.
Also, disclaimer, it worked for me. Do so at your own risk.