SMT × FE - Japan ; XBCX - West; Overall - XBC:X , but both will between 500k and 1 mil lifetime.

japan loves boobs so yeah, I mean, murica loves boobs, but japan looooooooooooooves boobs.

Xenoblade X is my most anticipated game for the Wii U, outpacing Zelda Wii U because, I have yet to see enough of that one.

That being said, SMT x FE or Illusionary Revelations #FE or whatever they call it when they bring it to the West, is more along the lines of popular for the Japanese audiences, with the anime style character designs, to the urban fantasy story with heavy JPOP/Japanese entertainment culture then the pseudo-MMORPG with a space sci-fi style that Xenoblade X brings to the table.

I think it will do better in Japan

I think there's one factor going against SMT x FE that wasn't applicable to XCX: how many people in Japan that own a Wii U also own a PS3 or a PS4? This is a number that would be helpful if anyone can point to a survey or something. 

This is important because, in Japan, SMT x FE is slated to come out at approximately the same time as Persona 5. It is safe to assume that there is a great deal of crossover between fans of both series. Also, since both games are 'hardcore,' it's arguable that the fans of the series would be more likely to have multiple consoles. Consequently, it is arguable that the sales of Persona 5 will cannibalize the sales of SMT x FE, something that XCX didn't have to face.

Of course, if Atlus has any control in determining when the games will release, they will actively try to put the games as far away from each other to maximize sales for themselves. It is likely that Nintendo has more direct and active control over the production of SMT x FE than Sony does over Persona 5 (which is probably just limited to the PS4 port, marketing, and/or localization, if anything), so I'm assuming that if there's any push to release either game at any point, it's by Nintendo and only for SMT x FE.

Yes it will :)
100% sure :P

Yes, but like others have said XCX should outsell it in the West.

SMT x FE will have waifu power, therefore it will sell more than Xenoblade.

You nailed it.

Whereas this is true... if Persona 5 does take away most of SMT x FE's sales, assuming they release around the same timeframe, it just means SMT x FE will have better legs. This is normally what happens. Most people own a PS4 or Xbox One as their primary console, and have a Wii U as their secondary console. They usually prioritize the games on those consoles first BEFORE getting Nintendo's games. Which is one reason why Nintendo games have amazing legs but not as good FW. 

That being said, I do not think Persona 5 and SMT x FE will release around the same time.