I would disagree. By the end of this year, I can name 13 CoD games that will have released (CoD, CoD2, Big Red One, CoD3, CoD4:MW, WaW, MW2, MW: Mobilised, Black Ops, MW3, BO2, BO: Declassified, Ghosts), hence an average of 1.3 per year. I don't think it is fair to include the Zombie games as I understand the gameplay is fairly different, so they are excluded.
On the other hand, I can name 17 Mario platformers since 1985 (SMB, SMB2, SMB2:USA, SMB3, SML, SMW, SML2, SM64, SMS, NSMB, SMG, NSMBWii, SMG2, 3DLand, NSMB2, NSMBU, 3DWorld), which is one every 1.6 years. I'm excluding Yoshi's Island as I consider it a separate series, and similarly the Wario Land titles.
That's not to say I don't think Nintendo has made some major missteps handling the Mario platformer series; personally, I see releasing NSMB2 when they did as a bad move and should've been released late next year, 2 years after NSMBU. But imo to consider it in the same league as CoD is ludicrous.