You missed something fairly big. The achievement command for scoreboards. Using TAB completion results in it exceeding the maximum chat history. There's also the summon command. These'll be useful to map makers and will bring about some really really neat stuff. Not too useful for the average player but I'd hardly consider it a "small" thing. (Sorry, I was kinda offended by the fact that the map making tools weren't listed and then was dismissed as a small addition)
Fishing Mechanics have also been overhauled. Water breathing potions will also be brewable with a special fish.
My opinion on upgrading: When we upgrade to 1.7 people that wish to see the new terrain can go out further in the world (personal recommendation: use the nether for quicker traveling). I really don't find a map reset that necessary since no mechanics or anything were changed. Any contraption built in 1.6 (and 1.5, for that matter) will work in 1.7. No real point in restarting since nothing will be broken by the update. Would just be unnecessary tears for what would be gone over a terrain update that, again, can be experienced by simply travelling outward.
