One of the things that came out of Nintendo's financial briefings was that we can expect  new "Mario Kart" and "Super Mario Bros." games this year for Wii U.  Some time ago, about the same time Miyamoto said he would like to make a new Link to the Past game, Nintendo secured the SuperMario4 domain.  If you click it, it just takes you to Nintendo.com

I think Nintendo will reveal Super Mario Bros 4 at e3.  It will be a modern 3D game.  It will have "bros." 2-player using the gamepad second screen.  It will have lots of retro and nostalgic elements, despite its 3D nature.  I think the 3D Mario direction was hinted at by Super Mario 3D Land.

I think SMB4 and aLttP2 were commissioned a couple years ago, and both will be wrapping up production this fall.

The SMB won't be titled #4. It will be a new 3D Mario game in line with M64, Sunshine, and Galaxies. However, your addition of a real second player sounds interesting, I like the coop mode where the 2nd player utilizes the gamepad.

But since they never used the number 4, I guess we could see that. Seems odd because in the Mario Kart series they went to a "7" which obviously included all the other MKs from various consoles that had no number designator.

pssst...Super Mario World IS Super Mario Bros. 4 :

http://www.mariowiki.com/images/0/04/SuperMarioWorldJapaneseBox.jpg

I think they're gonna pull out the old "4" to get some nostalgia. Expect some Tanooki suit action and more traditional levels in a 3D style. The 4 was used before, but only in SMW's original Japan release. I think they're going to ignore that and go with SMB4.

ALttP was also called Zelda III at first, but the have long since dropped that and now there is a LttP2 which isn't Zelda IV.

I kinda consider Super Mario World to be "Super Mario Bros. 4", or even NSMB Wii. 

But if you mean a brand new mainline sidescrolling Mario game that has an entirely new universe, and not recycled content (ahem, NSMB), then yes I agree, I can see Nintendo doing that, as well they should. The game would be a goldmine that would ignite Wii U sales, similar to how NSMB Wii reignited Wii sales in late 09.

I don't think it will be side-scrolling, but have side-scrolling elements.

Super Mario Bros games just means any home console Platformer with Mario. We'd be on Super Mario Bros 11 now. If they call it Super Mario Bros 4, it would just be a gimmick title that might get ignorant people to get more excited about it =P

I would like to see a Super Mario Bros. 4 game.  Without the  "flat" level design (where are all the secrets etc  that were up in the sky clouds etc???  And I also dont want the by now crappy music with all the WHAAA WHAAA sounds.....

Its somewhat funny Nintendo has several Mario  "IPs".

Mario Bros (old arcade game)
Super Mario Bros series
Super Mario World "series"
New Super Mario Bros series
Mario 3D Land
Super Mario Land series
Super Mario 64
Super Mario Sunshine
Super Mario Galaxy series


its not that they just change parts of the name everything is actually its own kind of IP.

The problem tho is that sometimes their "sequels" have like nothing to do with the original games.  Like Super Mario World 2: Yoshis Island. Or Super Mario Land 3: Wario Land   both games are actually introductions to spinoff series.

Nintendo should bring out some kind of Mushroom Kingdom Historia  book  so everything could make sense  lol

I hope not. I would love a real Kid Icarus 2.