This is actually a pretty cool update so I'll post everything here:

"Super Mario Maker will receive an update on March 9, Nintendo announced during its latest Nintendo Direct.

The update will come with a new "super expert" mode for its 100 Mario Challenge, which will unlock new Mystery Mushroom costumes. This unlocks after clearing expert mode and adds 6 more levels. Clearing these unlocks the new costumes.

It will also bring additional options for the level designer. These include Thwomp skewers from Super Mario World and mandatory boss battles, thanks to the addition of keys.

Nintendo also shared that more than 6.2 million courses have been uploaded since launch."

Also, pinks coins are going to be added. When you collect 5 a key will appear, so you can make levels that require finding all the coins in order to get they key to a door.

I have to say I'm excited for the keys because I like having mandatory boss battles in my levels

Don't forget about the red coins that are going to add a lot to levels as well.

Oh you are right, those coins are a pretty clever addition as well and will be part of some great leves, I'll try to make at least one level after the update.

As much as I wanted a 3D Mario Adventure, 3D World and this update in Mario Maker may make up the absence of one Wii U. I can't wait to play around with these updated tools!

Oh man, havent checked this thread for a while. I'll make sure to play your levels, and I will get back to SMM with the next update

Edit: oh, and here's my profile https://supermariomakerbookmark.nintendo.net/profile/Slarvax

Only 4 levels. And I apparently make really hard levels? 

If anyone else wants their Super Mario Maker bookmark in the thread just post it (I will update with the ones already shared)

I promise I will play this game again post update, maybe!

My levels aren't getting much playthroughs or Stars anymore so this update couldn't come any sooner. Hopefully it'll get some more player to play this again.

The keys and coins are a good addition. I could have used them in some of my levels, the thwomp pillar thing too... Too bad you can't update old levels (without reuploading), but at least I can get to use them in a new level I was working on. Just in time too, because at least the coins fit the idea.

The update looks very good. Gonna try it.

I made a new level using the new things. I just named it "New Mechanics." It is fairly difficult, but I tried to make it somewhat forgiving as well.