I've been carrying on with some of these for a while...
But here's my list of wants for LJ.
1) Some way to export everything on your journal -- including comments, images, etc -- to either a backup file, or XML.
2) The ability to have a post "expire" after a while, i.e. "this is public for a week, then it goes friends-only", or "friends for a week, then it goes private". Sometimes you don't want a new friend to be able to scroll through seven years of your history.
3) Inverse friends lists. I.e. show this entry to "all friends BUT these". Or "All my local friends" but NOT "the harry potter fans" (because there are spoilers).
4) Friends-only TAGS...Such that you can make a post like 'I'm pregnant!<lj-restrict="friends">It's my bosses!</lj-restrict>' This would really help when you have an obnoxiously vague post (no, I'm not going to link) and would like to pass more info to the parties that are affected by your vague posting, because, you know, you can't be bothered to make two posts...or send an IM or an e-mail.
That's all I can think of right now.
1) The inability to go back through your own LJ for more than 60 entries. LJ Claims this is for "performance reasons".
2) The inability to hide private/friends entries in your calendar view. People can't view them, but they'd know that you made them.
3) When viewing a syndicated journal, it looks like this. LJ has already bothered to read and parse the entries. Why not display them in something more fitting to the standard LJ look and feel? It's not like we have a single clearly defined standard for how a feed should look. If we did, every syndicated page on the web wouldn't have three goddamned different formats.
4) No sort-by-reverse. So often, I've wanted to read back through someone's journal, say a few weeks ago, and read what's been happening to them CHRONOLOGICALLY. With the current "recent first" layout. It means scroll to the bottom, scroll up, scroll down as you read, scroll further up to the next recent entry, etc. Yes, I know entries are sorted in chrono order in DAY view.
5) When viewing entries day-by-day, instead of "next day", can I have a link that says "next day that ACTUALLY HAS POSTS"?
6) Lack of any decent search functions for searching your own history (or someone else's) -- ideally this would be the kind of thing you would want to limit to public/friends/private. (and also be able to opt individual entries out of the search). Remember, people can still screenscrape your journal and read everything, this just makes life easy.
7) Inability to, on a syndicated feed, specify default icons (hell, even the option to pick one of your OWN icons for it would be fine).
8) When adding a syndicated feed, all the entries should NOT all show up at once in your friends list, to start off. It's perl goddammit, parse the fucking date!
9) The inability to have "negative friends lists". I.e. a list of "all friends (by default) except X". Useful when planning parties, ranting without hurting feelings, or making posts on subject matter that some people just don't want to read, when the surprising default do. (the concept being, new friends don't have to be added to the filter, they're on by default unless they're taken out).
10) The inability to download all your entries *with comments*.
11) This is so simple, really. Why is it all the default "by-day" styles have their navigation at the bottom. An additional navigation bar on the top would mean that you could jump through entries (of less than a screenful) without ever moving the mouse. It doesn't sound annoying until you do it.