No, it is not patch day.  However, if you go to your World of Warcraft folder and click the Background Downloader icon, you will begin to download 247MB.  If you are going to sleep or will not be playing for a while, click the Background Downloader to start seeding and downloading the patch.

Once Patch day arrives, you will have gotten a heads up to make your installation of Patch 2.1 easier.  Black Temple, Mount Hyjal and other Solo Questing features will be available—and most importantly … your odyssey to grind the PvE Nether Drake Flying Mount.

The quest starts with Mordenai, who wanders the southern side of the Netherwing Fields in Shadowmoon Valley.  Once you get neutral with the Netherwing Faction, the first requirement to get new quests is to have 300 Riding Skill—so start grinding your 5000 mount if you really wanna give it a shot.