It seems odd to have a global editor tab length setting and not per syntax settings. Maybe I’m just weird, but I like very different tab behavior between Ruby/HTML/CSS and what have you. For example, Ruby is kept two length soft tab, most other things I like four length hard tabs.
Along with this tabs-to-spaces and spaces-to-tabs commands would be great (I see some plugins for this already, but it seems like standard editor fare).
Even more awesome would be smart pasting, where it guesses the indentation/tab settings of what is being pasted in and converts it for the syntax being pasted into.