This feature is long overdue. The note taking app on my Palm Pilot 20 years ago had the ability to expand and collapse bullet lists, so I'm sure the devs at EN can sort this. It's also a feature of many XML editors, so it's not beyond the wit of man. Also, OneNote has this (and native pen support on a tablet), so excuses that it's 'difficult to implement' don't hold much water IMO. If Microsoft can do it with OneNote, there's no reason Evernote can't knock this out of the park very easily.
I totally agree with this requirement. I've largely switched to OneNote because of Evernote's lack of pen support. I much prefer to sketch and take handwritten notes in meetings, when I@m brainstorming, etc, as I find it quicker and more intuitive and flexible than having to type everything. Evernote's lack of handwriting/sketching integation has become a bit of a show stopper for me. OneNote handles it beautifully.