We still don't know anything for sure, for example TP HD is announced only 3-4 months before launch.

That's not exactly a major project though. 

I'm not saying it's impossible for Pikmin 4 to come to Wii U, just that from where I stand, it looks unlikely.

Again, big game that can be made in short time with little resources for Wii U. Nintendo will make money on this game and Wii U owners will happy because Nintendo supporting system like they said. Win-Win situation.

I am not saying that game is 100% coming on Wii U, but I say therea are good chances for something like that.

Even with some reused assets from Pikmin 3, new maps, enemies, story content, mechanics, etc would still not be a low budget project.

I think we're passed the point of getting Wii U games that aren't low budget or late ports/localizations.

What you think when you say low budget, certainly bigger budget than Mario Tennis or Amiibo Festival, but low budget in comparison with Zelda, Mario 3D, Smash. Bros, completely new Pikmin game, very likely smaller budget than Yoshi Wooly World for instance or some other 2D Nintendo game.

By low budget, yeah, I mean stuff like Mario Tennis, Amiibo Festival, Twilight Princess HD.

Pikmin 4 would be cheap compared something Zelda U or Xenoblade, but it would still be a medium-sized project, similar to the likes of Splatoon.

Mario Tennis, Amiibo Festival are very low budget projects, that games could be made for less than 6 months. So there is not really games that you can compare with them,I think even TP HD has much bigger budget. Zelda U and X are probably bigest Wii U projects, also not good comparing, Splatoon isn't also good comparison because they continue to work even after launch.

About Pikmin 4 for Wii U think about 1/3 of Pikmin 3 budget. Like said they already have Pikmin 3 enigine, assets and models, and for Pikmin 4 they just need new levels, few new enemies and bosses, one or the new mechanics, and story. Not to mention that team that developed first game for Wii U is very familiar with Wii U architecture and Pikmin development process, so whole development process for Pikmin 4 onw Wii U would be very fast.

Like I wrote on first place, very similar situation with GC Pikmin games and think that Miyamoto wants to do same thing on Wii U too.

It was a very different situation on GC, making games for that level of hardware is easier than on Wii U. GC also wasn't selling as badly as Wii U is, and Pikmin 2 arrived over a year and half before the GC was replaced, so there was no pressure to bump it to the next generation like there is now with Pikmin 4.

Of Course that was easier to make games for GC than for Wii U, but that change anything. GC was worst selling Nintendo console till date and Wii U is now worst selling console till date, Wii U will have shorter life than GC so Nintendo needs to support it to the end. We had Pikmin on GC, than Nintendo make sequel using same engine, assets and models. Nintendo probably is doing same for Wii U. So that's very similar not very different situation.

GC in 2004 was in a much less desperate position than Wii U will be in 2016. 

There's a significant difference between a system 19 months from replacement and on course to sell 22 million and a system in its final 6 months and on course to sell 14 million.