Looking at the numbers for the past little while, it occurs to me that Malstrom may have overestimated 2-D Mario to some degree.
No question that New Super Mario Bros. Wii is enormous, and pretending otherwise is the height of foolishness; I expect it to neatly break into the top 10 for best-selling titles this generation, even with combined SKUs.
I remember him calling it the "biggest franchise in gaming," though, specifically mentioning it as being larger than Mario Kart and possibly even Wii Sports - I can't remember if he mentioned Call of Duty or not. Call of Duty would be included, though, thanks to use of absolute terms.
But sales numbers don't suggest that: Call of Duty has been selling more per week very nearly since the game launched, and though NSMBWii pulled ahead for a time the sales levels shifted back into Modern Warfare 2's favor some time ago.
It's difficulty to tell whether or not NSMBWii will ever pass up Modern Warfare 2. I have my doubts. Claiming that 2D Mario is bigger than the aforementioned franchises - Mario Kart, Wii Sports, and Call of Duty - seems like it may have been premature.
Not to take away from it in any way, but I was looking through numbers to update my Top 50 topic and this kind of jumped out at me.