You nailed it.  Especially the bit on "modal" power ups.  Power ups should always be optional, because when they are optional they have an intrinsic user-creative flair to them.  You CHOOSE how to use it.  Also, when a power up is required, its features cater to that requirement and thus tend not to have multiple uses.  Yoshi had many uses when introduced - acted as a second jump, swallow enemies, spit them out at enemies, act as a mushroom (taking a second hit), and had the ability to take in different shell power ups.   Cloud Mario was sort of cool (too many jumps imo), but resulted in bland stages - they should have just given you the power up and not made any stages catering towards it.  The spin jump from SMW was cool also because it had multiple uses and was NEVER required since it lost its effect when small anyways.  The player needs avenues to express their creative take on how to play.

I made a post earlier about how developers need to let loose with their imagination when it comes to new worlds.  Hybrids are an easy place to start if you can't even think of anything and many fictional universes extract from such sources.  

I think the only stages that change like that are the ones I mentioned and the one you mentioned (I actually forgot about that, since starting with Chill Penguin is a no-brainer for me because of the Dash upgrade [can't see why they couldn't just give them during the intro stage]), but yeah, it's pretty neat. I would love to see that kind of stuff used in a bigger way, like, say, in a mainline Super Mario game.

You and Soleron pretty much summed up all of my problems with the NSMB games: the same old element-themed worlds, the recycled carousel music (show of hands: who here wasn't already tired of this theme by 2009?) and the general feeling that Nintendo isn't even trying.

Dont tinker with Mario its fine the way it is, just give him a little holiday at isle Delphino to recharge his batteries. Then after a couple or three years we will be pining for the next Mario game...sometimes you can get too much of a good thing.

The devs of Mario Games should get inspiration from Retro Studios' Donkey Kong Contry Returns on the Wii. That game was a master piece. It's the best platformer of 2010 hands down. I would say abandon the *New* Super Mario series and start making 2D Mario fresh again.

You should pad this out a bit more and make it into the OP for a thread.  

I think they made a big mistake with NSMB 2. It should have been based on the US version of the NES classic SMB 2. I don't care that it's built on top of Doki Doki Panic. It's a better game than the Japanese SMB 2 and it's still one of the best classic Mario games. Then NSMB 3 could be based on SMB 3 and NSMB 4 would be based on Mario World and so one.

Koopa finally got a hold of Mario and realized that in order to finally stop him he needs to rid him from what he uses the most: his legs to jump over his enemies. So Koopa eats Mario's legs and leaves him to bleed to death.

Princess Peach, now impregnated with the seed of Koopa, will give birth to the AntiChrist so Mario, realizing Luigi is too much of a pussy to save the world by himself, realizes that "death can kind of wait" given the present circumstances so he pushes forward, dragging his body through the floor and killing his enemies by eating his heads instead of jumping on them.

Instead of coins, Mario now collects "Blood Pints" to keep himself from bleeding to death and, when in possession of +100 points in Blood Pints he can unleash a powerful blood-whirlpool attack that shall be dubbed the Menstrual Madness.

The thought struck me (and still does), but I think I need to broaden the subject for good discussion to come out of it.

The next game of the series should be called "New Super Mario Bros. Galaxy" - there, all problems solved! Or, another solution: let Miyamoto do the game from scratch all alone (except the programming)!

Anyways, what Nintendo really should do is take a step back and ask themselves: "What would a Mario game look like if we had done it back in '85 with all the abilities and resources we have TODAY".

I think they should just continue to do what they're doing.

People let nostalgia (and the classic visual style) affects them, imo, and do not acknowledge that NSMB was one of the (if not the) most innovative Marios of all. For lots of reasons, but the main ones are:

1 - Gameplay... lots of changes, but just by adding the the kick wall move it changed the dynamics completely. Just try to remember the amount of deaths you saved because of that (and the spectacular ways you did it) and the amouts of stages that needed it.

2 - It introduced the definitive concept of mario level design: 1 stage/1 gimmick (in a good way)
The amount of variety surpasses any mario combined. Just compare open mindedly to see what I mean. Each and every stage had it's own "thing".

I can't wait to play NSMB2... they always make new "things" to do on stages