Here is the argument transcript page, and the downloadable mp3 audio-stream, itself, from Chicago-Kent College of Law. This is nearly a month earlier than the Court's usual website releases, itself. [Cite this stream as: The Oyez Project at IIT Chicago-Kent College of Law. 23 March 2012.]
Sadly for Mr. Howards, my personal take is that there aren't five votes to send the case to trial on the merits. Which means there likely aren't five votes to depose Mr. Cheney about his orders, and whether he felt threatened by Mr. Howards that day in 2006 in Pitkin County, Colorado.
There are probably five votes saying we should not force Secret Service agents to make instant decisions as to whether Mr. Cheney's orders were intended to protect the office, or punish a speaker for his point of view. I am not sure that five votes feel that probable cause allowed everything that followed -- as the government's lawyers urged.