things tumblr needs to add:
- lockable posts (so you can make a post unrebloggable)
- when deleting a post, it deletes everywhere else.
- proper block button, if twitter can do it, so can you.
- proper reporting guidelines
also searching multiple tags at once would be wonderful
And the ability to track url tags with hyphens yes good
How about a real message system. The one thing they could really steal/borrow from Yahoo.