Earlier this month we saw OS 18.104.22.1687 for the BlackBerry 9900 and now we have the OS leak for the 9850. We heard a rumor this maybe pushed out later by Verizon but if you can’t wait for that you can pick up the OS from the following link.
From what we hear this one will have the media server option, if you do install let us know how it works for you. Note that this is not an official OS.
Disclaimer: This is not an official OS, and can render your devices inoperable if you do not know what you are doing. If you do install, do so at your own risk.