The first update for AutoCAD 2012 is now available on the Autodesk site. As usual, read the readme first and exercise the usual paranoia. Make sure you install the right version (32 or 64 bit). The update is also available for AutoCAD LT 2012. There is no news yet on equivalent updates for vertical variants of AutoCAD, so just talk amongst yourselves for a while until Autodesk gets around to it.
Autodesk has, thankfully, abandoned the confusing nomenclature for its service packs. So this is not 2012 Update 1 with a filename that includes SP1 and which results in the software being considered 2012 Version 2. It is 2012 Service Pack 1 with a filename that includes SP1 and which results in the software being considered 2012 SP1. Why Autodesk thought the former convention made sense is beyond me, but at least it’s over now.
This Service Pack is unusual for more than that, though. It’s the first free update since R13c4 in 1996 to include new functionality, i.e. a new command (ARRAYCLASSIC) and a new system variable (SNAPGRIDLEGACY). I’ll have more to say on that later.