Since slim launch PS3 was outselling x360 by 100k on average per week:
http://vgchartz.com/hwcomps.php?cons1=Wii®1=------&cons2=PS3®2=All&cons3=X360®3=All&start=40055&end=40167
250k vs 150k.
Latest x360 boost was not only due holiday season(same for ps3), but also 99$ walmart deal, MW2 bundle, ban wave and other things, which we are probably not going to see in first part of 2010.
52 weeks with 100k = 5.2 mln. for PS3.
If in first part of 2010 there won`t be new x360 pricecut or new bundles, then with GT5 help PS3 will continue outselling x360 by 100k per week on average.