Found this through google:
ESPNU HD is a 720p high definition simulcast of ESPNU that launched on August 28, 2008 to coincide with the start of the College Football season.  The service debuted with the football game between Vanderbilt and Miami University. Time Warner Cable, Verizon FiOS, Blue Ridge Communications, Atlantic Broadband and Broadstripe carried the HD channel at the launch date.  In late 2008, AT&T U-Verse added it. Bright House Networks began adding the HD channel on a regional basis on November 7, 2009.  Cablevision added it on March 23, 2010.  DirecTV added the HD channel on May 19, 2010.
So Comcast & Dish don't have the HD version yet.