Today Nintendo announced that they'd be including 5 new features in an update happening on 11/4.
- They've finally added checkpoints
- You can now have question blocks give you a Super Mushroom when you're small or a Fire Flower when big
- There's now a more challenging version of Gnat Attack
- A new tab for Official Nintendo made courses
- A new area for "Event Courses" which will be worldwide challenges it sounds like
Pretty awesome stuff. At least this shows that Nintendo plans on supporting Mario Maker after release. So who knows what they'll add next. I know lots of people want slopes.