depends a lot in which 3rd p dev is porting it, could be a great one or a noob cheap one,
and how much effort are putting on it....
time will tell i guess

That qualifies more on the lines of a "remake," which is a different kettle of fish.

The problem is you're not really right, you are cherry picking one game and totally ignoring all the games that have been outsourced ported and turned out great. I see your Orange BOx and raise you Sly Collection, Mass Effect 1 PC, Bioshock PS3, Elder Scrolls Oblivion PS3, which turned out better than what the actual dev teams did for that system. and the list goes on and on. A lot more often than not the games turn out fine

Deus Ex: Human Revolution PC was outsourced and was better as well...

There's cases supporting both sides...

Oniyide already effectively answered this.

I thought the outsourcing was the cause of the biggest problems with Deus Ex? Primarily the boss fights.

that has nothing to do with the port...  The PC port was done by nixxes, and added things like hotbar,console with cheats, to make it like the first deus ex. 

the boss fights were done by GRIP, they weren't worse than the boss fights in Mass Effect (which admittedly isn't saying much). Didn't fit in the game though.

so, the problem is that a port for a system which will have only few million sold units after release isn't made by the team who should already work on the next big game and maybe dlc's for all systems?

but since you agreed in the other thread that ea games are crap and you hope nobody buys ea games for wii u why do you even care about it? shouldn't you be happy if the port will be bad? that would mean less sales for ea and less people buying an ea game for wii u, exactly what you want.