Here are the most important things on my book I'm currently missing
mobile app
marketplace (in development)
escrow (in development)
messaging (in development for GUI)
down votes stake based. (do not hide posts for newbie dv's)
restrict accounts with less than 20 SP (eg 1 post per hour, commenting every 10 mins)
better wallet overview (example add a ticking $D interest counter, explain payouts)
add clickable links to history payout posts
add follower stream
add mute lists and make them follow-able via proxy
language filters
addthis.com sharing buttons
post stats / analytics
referral program
a blog page where the user can decide which posts to show
night mode theme
ipfs images integration
I do think that people with less than a certain amount of steempower should be limited in how many posts they can make per day. That would encourage them to invest and post more and help steemit financially or to post more meaningful things and help add value to the community. Memes and jokes are great but when you compare that with a well thought out heart felt post there is not a whole lot of value added in the latter in my opinion. But what's great about steemit is that if someone disagrees with me they have the power to reward any content they find interesting or entertaining.