What will sell more, Hyrule Warriors (Wii U) or Samurai Warriors 4 ( PS3, PS4 and VIta)?

Sales predictions?

This is something I cant answer myself, knowing nothing about the series. But I'm interested to hear your opinions.

Hard to say, Samurai Warriors isn't getting English dubs only subs so that may effect the sales.

Are we talking worldwide?
I think Hyrule Warriors just, not because of us Musou fans but the Zelda fans who buy the game having never really played the Musou series.
Anyway I will pick up both for WiiU and PS4 respectively.

Hyrule Warriors ez just cause of the Zelda brand

Oh dear, yeah that's gonna be an issue.

Hyrule Warriors does seem to be getting much more hype as well.

Well right now the install base potential is like 100m vs. 6.5m sooo.. Actually no. I'm gonna say Hyrule Warriors. Never underestimate the power of a Nintendo franchise.

Hyrule Warriors. There's more hype for it and the success of a Warriors game depends on the skin you slap on it. See One Piece Pirate Warriors, which sold 600k+ in its first week alone. Hyrule Warriors will likely see similar success, even if the install base is really small. Definitely don't underestimate the power of Nintendo franchises.

Hyrule Warriors. There are hundreds of thousands of Zelda customers who will buy it for the name on the box, and quite a few more musou fans who would buy it anyway Personally I'm looking forward to SW4 much more, but I think HW should do very well, could hit ~1million, which would be in the same ballpark as the first One Piece Musou game and DW7.

Personally what I'm more interested in is will HW convert some Zelda fans into Musou fans and grow the other subseries. Given that one is Nintendo exclusive and the other is basically a PS title (well, its on XB1, but it won't sell gangbusters there and there have been some 3DS spin-offs), the odds seem stacked against it, but I guess you have to hope.

The only thing which is a little concerning is how badly Ken's Rage 2 and Warriors Orochi 3 Hyper bombed on WiiU, but having seen some of the hype for HW, it should avoid that fate

I think Hyrule Warriors. Samurai is great though, but only played one of them.

Hyrule Warriors, probabily sell 300,000 first week and 600,000 in total(this only in Japan).