Oh my, this is my absolute favorite scene. Thank you for bringing it up, I nearly forgot about it!
I think that article takes a really interesting angle on possible outcomes. I certainly never thought much about Esther's humanity spell. It could definitely be used for an awesome arc, especially for Damon. If it does happen on the show, I see it being more along the lines of a failed attempt, rather than actually turning him back to human.
I don't know if this has been brought up yet, but what do you guys think of that blind spoiler about a couple sealing the deal? source
Something about it makes me think of Damon and Elena...