X360 - Halo: Reach 4,049,971 (Worldwide)
DS - Pokémon Black / White Version 2,609,129 (Japan Only)

It only needs ~1,45 M combined on US and Europe to do so, about 725K for each territory. And I'm already putting Australia outta this.

I think Reach might not last too long in the throne of the biggest single platform launch ever.

I think it will beat Reach. 

Thoughts?

It's a no brainer! Pokemon is a way bigger franchise than what Halo could ever be. So of course it would and it will have longer legs.

Looks like it. For me Black and White is day 1. 

Modern Warfare 2 holds this record anyway

yeah.

________

and yes it will beat Reach

I hope so!

most likely it will. and to the people that say that its two games. the differences are ALWAYS minimal. It´s basically just one game.anyone who disagrees has probably never played pokemon

Well unless halo doesnt get waaaay adjusted then yeah!!! :D

Last Pokemon sales... Pokémon Heart Gold / Soul Silver Version (DS)...

NA: 1,032,118
EU: 477,286

So tie??? But this Pokémon was a remake.

Another one... Pokémon Diamond / Pearl Version (DS)...

NA: 1,362,580
EU: 483,196

So yes ;)

I think it could, in fact I'd say it's likely. I think this has the potential to be the biggest Pokemon yet.