I must say, when I first started using TextMate I had no idea all the commands even exited. And even now, after I've developed a fully functional bundle of my own, I'm still discovering things about TextMate that are kind of hidden.
Clearly Allan wants the app to be completely transparent, that the code should be the most important focus of what you are doing and that the interface should completely disappear and become an extension of the code itself. And that's what I love about TextMate.
That being said, I think more needs to be done to expose the true power of TextMate to people who are unaware of that fact that commands in multiple bundles could apply to what they are doing. I often don't know of all the possible commands that I could be using at any given time. Aggregating those commands into a list so that people can see what is possible, given the current scope, would be a good thing I think. Be that in a drawer, palette, floating box, whatever. And I don't think that that would significantly impact the transparency of the app.