I saw an older list somewhere on the network but it was missing a few key things that imo, would make Ning even better than it is!
Mentions - Ability to mention members of the community in updates, posts, in chats, basically anywhere on the network.
Share/Reshare - Ability to share and reshare what others have already posted. So if I was on someone's page and saw that they posted something I really liked two months ago, I could reshare it and have it show up in the activity feed and elsewhere...
Update Likes - Can we please have it that almost everything has the like feature available? So events, comments, messages in chats, etc...
Friend-Only Activity - Would be great if there was a way to see the latest activity of only friends. This could be an option in addition to the current way, which shows stuff from everyone even if you're not friends.
Upload Photos/Videos right into Activity Stream - Unless I'm mistaken, I don't believe we have this feature yet.
Update Polls by allowing folks to poll right in the activity stream. Also, the polls feature doesn't seem to allow you to add as a module to another page. By this I mean, you can select it as a module on a page sure, but nothing shows up.
Notifications - If someone comments on something I've posted or a status update, I should receive a notification right on the site and in email that someone has commented.
Last but definitely not least,
Custom App - I would be willing to pay a lot more to have a custom app for my community... one that would provide rel-time notifications, etc. & I'm quite certain that I'm not the only one who would love this.
Anyway, these are just a few suggestions that will hopefully be considered in the near future....maybe not the last one but definitely the others :).