6 - Guess Guess Revolution

GBA           June         11, 2001

Pokémon Ruby and Sapphire          March      19, 2003

SP             March       23, 2003

Pokémon FireRed and LeafGreen    September 9, 2004

Pokémon Emerald                          May            1, 2005

Micro       September  19, 2005

DS            November  21, 2004
Lite           June          11, 2006

Pokémon Diamond and Pearl          April        22, 2007

Pokémon Platinum                          March      22, 2009

i               April            5, 2009

Pokémon HeartGold and SoulSilver March      14, 2010

XL            March        28, 2010

Pokémon Black and White               March        6, 2011

3DS         March               2011

With this crudely formatted text as a guide, we should expect:

Spring           2013 - 3DS hardware revision
Spring           2013 - Pokémon Gen VI
Spring           2015 - Pokémon Gen VI 3rd version
Spring 2015/2016 - 3DS 2nd hardware revision

RSEmakes are up in the air, as these past two gens were irregular for remakes. Maybe I'll come back and add GB/C, GBA, and Gen I and II, to compare. Always, the most thrilling question for me is,
What's next?