For those running stock or rooted stock, 4.1.2 was just released and is starting to roll out. It supposedly brings some performance improvements as well as landscape mode.
The few who have gotten it over at XDA are reporting that it will install through CWM recovery, myself included.
If I get it, I'll link to the file here. If someone else who is rooted gets the OTA, the .zip file normally downloads into the /cache directory - feel free to copy and link it here.
The file should be around 31.3 mb in size.
Link (if you're on JRO03D): http://android.clients.google.com/pa...D.03a4eaf9.zip (you must be on JRO03D to use this particular file, S users will have to wait for their OTA file, or flash back to D then run this)
Thanks to styckx over at XDA for determining that link from the filename of another user's logs.