wow, there has been a ton of threads about head tracking lately.
well, despite Johnny Lee making it a popular topic, head tracking has been around in one way or another for a long time. Here are 4 patents on head tracking i found in a few minutes of looking. note that these patents go back into the 1990's and none of them are patented by Nintendo, Sony, or Microsoft.
in the end, it's not a technology that's going to limit the implementation of this technology into games...it's going to be which company has the biggest balls to take a risk bringing this technology to market. I'd guess either nintendo or sony.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=6&f=G&l=50&co1=AND&d=PTXT&s1=%22head+tracking%22&OS=%22head+tracking%22&RS=%22head+tracking%22
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=7&f=G&l=50&co1=AND&d=PTXT&s1=%22head+tracking%22&OS=%22head+tracking%22&RS=%22head+tracking%22
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&co1=AND&d=PTXT&s1=%22head+tracking%22&OS=%22head+tracking%22&RS=%22head+tracking%22
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=12&f=G&l=50&co1=AND&d=PTXT&s1=%22head+tracking%22&OS=%22head+tracking%22&RS=%22head+tracking%22
