Kodak has decided not to participate in the PMA 2011 show in Las Vegas (September 8-10th, 2011). So far Sony, Panasonic and Fujifilm have confirmed their commitment to the show. In this year's PMA 2010, it was Leica that decided not to participate. Canon also initially announced that they will not be part of PMA 2010, but then changed their mind.
Update: the initial source of this information was the PEN newsletter from December 6th, 2010:
After some clarifications from PMA, it seems that the presented information was wrong and was referring to the PMA Australia event and not the US PMA 2011 that will take place in Las Vegas during September of 2011:
"The event Mr. Marshall is referring to is our PMA Australia event, the "Imaging and Entertainment Expo," June 23-26, 2011, in Sydney, Australia. Mr. Marshall does not speak for PMA, and any announcements of PMA 2011 exhibitors would originate from PMA here in Jackson, Mich."