well, (limiting myself to america)...
last year 360 sold ~275k to ps3's ~175k units on black friday.
yoy for last weeks sales: 360 is negative by 27k units or 16% and ps3 is negative 22k units or 22%.
so i'd predict this black friday 360 sells in the ballpark of 230k units and ps3 sells 135k units.
therefore 360 outsells the ps3 by ~95k units or a ratio of 1.7 to 1.
just for fun: last year wii sold 440k units on black friday with a yoy of positive 25% for last week's sales.
so i'd say the wii sells a minimum of 550k (i through in minimum because supply will not be nearly as constraint as last year) meaning he wii outsells the 360 by at least 320k units or a ratio of 2.4 to 1 in favor of the wii. xD
numbers from: http://www.vgchartz.com/hwcomps.php?cons1=Wii®1=America&cons2=PS3®2=America&cons3=X360®3=America&start=39327&end=39768
