Uncharted 3 sold probably 7m by now (VGC never update software after a certain point as shown by LBP still being under 6m despite being announced as a 7m seller) and the highest selling Halo is Halo 3 with 12m.  Uncharted has increased in popularity with each release.  Halo isn't THAT much bigger anymore as these numbers show

Given the difference in userbase, Uncharted may even become as big as Halo this generation. Assuming that Uncharted 4 won't be the last game.

I have a feeling Uncharted 4: A THEIFS END will be the last one at least for awhile.  ND has left big franchises behind before when they're done with their story (though a new Jak would be awesome or if they bought back Crash).  I do however think it will be their best game yet given that they know it's the last one (I think each iteration made by ND has gotten better already) and will reach new heights on PS4.  Naughty Dog will be determined to make Drake's end the biggest bang to finish a series we've seen yet because they simply won't let it end on a whimper.

Your numbers are probably incorrect and both consoles will sell higher in their respective timelines, though your prediction is probably correct.

They have left big franchises before but they kept them in a single generation. They are continuing with Uncharted in a new generation though. Who knows. I guess even themselves don't at the moment. Uncharted 4 is still far away.

I'd like them to continue with a new franchise, but it is difficult the let Uncharted go. So many great games, countless hours in multiplayer etc. I am happy either way.

I think you underestimate the effect price parity will have when new Assassins Creed, COD, Fifa etc comes out (MS will probably undercut sony with bundles too). Also the matter that the PS4 and XO have had atrociously bad 3rd party support for new systems, which was especially evident in the XO system sales thus far. Finally the matter that the XO has a better holiday line up then the PS4.

You added a 1m bump but I don't think its generous enough ;p

I think it will do 9m by this years end and 11m next (20m in total). Whereas the PS4 will probably do 16m by the end of this year as you suggested.

I was gonna call this ridiculous but the math seems sound.

Its a safe bet.....I think :)

oh me too and I think they probably wanted to end with a bang so they came back for one more (since many call Uncharted 3 a disappointment even though it got 92 on meta and is my favorite of the series).  Also Uncharted has been their biggEST franchise so far (since they didn't own Crash technically I'll give it the edge) and Sony probably wanted them to sell some PS4s unless they REALLY couldn't get themselves up for it.  Also ND wants to see what they can do on PS4 with the franchise because let's be honest we all wanna see what GoW and Uncharted will look like lol

Halo is no joke, We will see.