(click to enlarge)

Super Mario Bros. Release History:

NES:
Super Mario Bros. - 1985
Super Mario Bros. 2 - 1986
Super Mario Bros. 3 - 1988

Gameboy:
Super Mario Land - 1989
Super Mario Land 2 - 1992

SNES:
Super Mario Bros. 4 (SMW) - 1990

N64:
Super Mario 64 - 1996

GC:
Super Mario Sunshine - 2002

DS:
New Super Mario Bros. - 2006

Wii:
Super Mario Galaxy - 2007

Opinion/Analysis:
The above shows the proximity of main-line flagship Mario titles released per system and the years in which they were released. Notably, the last time a direct sequel for a flagship Mario game appeared on the same system as its predecessor was NINETEEN HUNDRED AND NINETY-TWO. That's 16 years, fellas.

Clearly, NSMB is the best selling Mario title since the original (please refer to the amazing chart produced and maintained by Stumpokapow), so those that would argue that NSMB2 is bound for the DS would have a convincing argument.

So what do you think? Will Nintendo follow the last decade and a half of precedent or will they take advantage of the enormous install base of the DS? Will they actually make a direct sequel, or will they continue with their history of reinventing Mario for their next machine?