ps3 sales predictions

[Kantor]

TWRoO said:

PS3
end of 2008 - 21mil
end of 2009 - 33mil
end of 2010 - 42mil
end of 2011 - 49mil
end of 2012 - 53mil
end of 2013 - 55mil
end of 2014 - 56mil

360
end of 2008 - 26.5mil
end of 2009 - 35mil
end of 2010 - 41mil
end of 2011 - 46mil
end of 2012 - 49mil
end of 2013 - 50mil

Why will the PS3 and 360 sell 4 mil and 3 mil respectively in 2011?