It is, but that's because we have to have a solid editing experience for the "simple" stuff before we can do the more interesting things. What good is it to have these awesome function oriented editors when you can't even modify a file efficiently? :)

We use tabs as a simple way of wrapping up a context. In the future they will include all sorts of neat things - and they aren't limited in any way. If we want, we can drop an infinite canvas into one, or a codex (a document made of many parts of different files). So yes, right now we wanted something beautiful and efficient to use while live coding, but as I said in my bit about 0.4.0, the really interesting semantic-oriented stuff (functions and the like) is what's next!