As I said, it's not just a HD remake, but it's a Zelda remake. 

Consider OoT3D. The 3DS was in a similar scenario to the Wii U until this game came out, and consider the chanegs in sales when it released:

Japan: 67% increase

Europe: 10% increase (yet sales continued to increase from here, 17% and 23% the following weeks)

America: 117% increase

The game has now gone on to sell a pretty massive 3 million units, which is still selling (55k so far this year not including digital which was on offer, 600k last year) and you've got to remember that this game was for a handheld (which is never as big for Zelda), and is a remake of a game already avaliable on N64, GC and Wii. Wind Waker is only on GameCube, and it's looking to include a lot of features which weren't in the original, and I can see it increasing sales very significantly indeed. 

Also, Nintendo confirmed that both MK and 3D Mario will be playable at E3. So I'd imagine at least one, if not both, will be avaliable before the year is out, as well as who knows what other unknown titles. So this strong winter should mean that in November/December the Wii U should outsell the Vita by at least 100k a week on average, so about an extra million for the last 10 weeks. So all the Wii U needs to do is stay in touch until then. It's still technically sold more so far this year, so I don't see the Vita getting 1 million ahead before the end of October.

You think the Wii U will get a price cut and the Vita will not? It's only been cut $50 in one region.

I'm assuming the Vita is going to get a price cut, but I guess everyone else was. 

Even then the effects will likely be small, perhaps doubling-trebling numbers for a week or two before returning to roughly the same figure. 

WiiU has arguably more and bigger games coming later this year. What exactly does Vita have after Soul Sacrifice

Wii U should edge it out due to inevitable Mario games, Nintendo definitely have something in the pipeline.

Most likely another exclusive Assassin's Creed.

I don't think the Vita will outsell the Wii U, but I find your statement puzzling. There's no way in hell that the Vita would return to pre-price drop sales after two weeks. Even extended to a month, a price drop would do far more to elevate the sales floor for Vita. The longer Sony holds back, the closer more major releases are.

Big retailers around the globe already discounted Vita back in November...actually Vita is alive thanks to retailers cutting prices for holiday season...

yeah I'll try to remember to bump it

People seem to be assuming Sony will have nothing for E3 this year for Vita.  Soul Sacrifice, Tearaway, and Killzone aren't going to be the only games this year and the only reason we know all this stuff will be at E3 for Nintendo is because they had a direct in response to slow sales to basically announce their announcements.  Sony has a couple games but probably wants to hold back.  In the end it's not when you announce but when you release (this applies to PS4 and Nextbox too)

Perhaps a couple weeks is too short, but there's no game which I can see which can really go along with the price cut to push sales and to maintain them. Soul Sacrifice, as well as a few other smaller titles, was good in Japan, but in the West? Killzone arguably but I don't see that selling particularly well, maybe 750k tops. And that's it (TearAway will be great and I'm really looking forward to it, but it ain't a system seller). 

There's plenty of deals, unofficial price drops etc. for the Vita (there's some in my local game stores for £150 new, they were £239 at launch and they still aren't moving) because it's a device consumers just don't want. A price cut will help push some people on the fence into getting one, but will it entice the public? This I do not know, unless it's like $100/£80 with some major games like the 3DS one. But even then, delaying the price cut will put it up against Pokemon, and console games like GTA V, and they'll only ever be one winner there.

Also, you can't really cut the price of a system in the EU, because there's no fixed price. But as I mentioned, retailers are discounting prices but it's not really having an effect.

That's just my opinion. I hope I'm wrong because I like my Vita, but I don't see people really enjoying it. My friends who are gamers laugh it off when I mention it and even doubt that it still exsists they hear so little about it, and these people are serious gamers. Who knows what the attitude of the general public is, but I doubt it's a good one.