It will have a bunch exclusives but not as many as PS4 and X1.
Architecture has nothing to do with this - vast majority of exclusives comes from the first party studios (studios owned by the respective console manufacturer) and second parties (independent studio titles, published by the console manufacturer). There are some random third party (publishers like EA,Activision,Ubi etc) exclusives but from what I can tell Nintendo's are just shovel-ware (such as Carnival Games, variously branded "fitness" games, cartoon licensed titles etc.) while both Sony and MS enjoyed some AAA third party exclusives. There is no reason to believe the situation is going to change in the future - if anything it's going to be less of those since the major producer of Nintendo exclusive shovel-ware, THQ Inc, went bankrupt recently.
Out of the three console majors, Nintendo has the least first party studios - 7 (at least 3 of which are working on handhelds exclusively). Microsoft has the most. And Sony has the most first parties that actually ship games regularly.
So the only chance for Wii U to get more exclusives than PS4 is for Nintendo to contract a bunch of 2nd parties and/or sign a lot of exclusive contracts with the 3d parties. If this ever going to happen it's far from "likely" since it has not happened for the last 3 generations of consoles (Nintendo beating Sony on the exclusives).