Just saw this on twitter.
MacRumors.com (@MacRumors)
11/28/12, 12:41 PM
Intel Reports Fix Coming for Flickering on Monitors Connected to 2012 Mac Mini via HDMI
macrumo.rs/11eaHyH
Following last month's launch of new Mac mini models, a number of users in the MacRumors forums and Apple's support forums have cited issues with flickering on external monitors connected to their machines via HDMI. Connections via Thunderbolt/Mini DisplayPort are not affected.
The issue seems to be a known one related to the Intel HD 4000 graphics used in the Mac mini, and Intel has now acknowledged the issue in the Mac mini and indicated that a fix is on the way. A timeframe for a fix delivered through Apple is, however, so far unknown.
We are aware of the flickering issue, and there will be a fix provided in the future. The overall flicker issue is also being addressed here; http://communities.intel.com/thread/32932
Your OEM (Apple) will provide the driver with the fix when they are done configuring our driver (that has the fix). An ETA on this is currently unknown.
Apple has begun developer seeding of OS X 10.8.3 with an emphasis on graphics drivers, but it seems to be unclear at the present time whether the current beta version of OS X 10.8.3 contains the specific fix for this issue.