My list, with extensive use of "air quotes" to clarify my "wishes"

:
Sort of from Taun's list, but rendering the "output" of a camera onto a 3D surface. This would be even better if somehow the camera object referenced didn't have to be within visible range...so we could have "portals" to each teleport location at SWGZ and won't have to use static pictures

Also makes the SWSS much more fun to work on. Croquet Project has this ability already.
Ditch "Telegrams" for IMs, only persistant like how ICQ does it...meaning you don't have to be logged in to receive. Messages are just organized by who you're talking with, to reduce clutter and make it easier to communicate.
Mass-invites, I imagine this can't be too difficult to implement if the code already exists to invite one user.
A building command that lets us edit UV mapping would be hella useful. Or even just arguments for the "texture" command with x/y scale factors for the UV map.
This is getting more complex, but add logic into the building command system? The ability to perform different actions on create/bump/activate/etc. based on different conditions would be a very powerful feature.
While we're getting nitty-gritty, what about object action/description compression? Figure out some way to let us squeeze more bytes of commands into objects, or squeeze more objects into cells because each contains "less" data

First things that come to mind are storing commands with some sort of shorthand version that's not neccesarily user-friendly (it would be translated back in the object properties window anyway), or doing Huffman encoding on the description/action fields before storing to the DB. Even if this doesn't allow for more objects, it could speed up load times.
And finally...
MP3s/Audio that loop seamlessly!!!I've only been asking/promoting/whining-about this idea for 4-5 years now. And it's not just a "building" feature.
It can really break up an environment with a cool ambient noise loop if there's a regular 1-second silence to mark the beginning and end of the loop. Part of this is due to the MP3 codec (short silence added to beginning of file), but this is where exploring other codecs (like...Ogg Vorbis?) can be handy. I'm not experienced with how easy this is to implement, but if it won't take a significant amount of time then I really, really, really would like to see this (finally) happen.