I don't get what you mean by "if there is still enough interest". If you wanted a particular feature or change, couldn't you just fork Textmate and then implement it? That's the advantage of it going open-source. We are not at the mercy of some developers who don't think our requests are worthwhile. If I want something on top of my open-source editor of choice, I can just "get up to speed" [1] with the source and go ahead and implement what I want.
I do think we rely a little too much on other people to do things that we want for ourselves. If you really want a feature and no one else offers to do it, then you will have to pony up and do the legwork yourself. And that's a good thing.
[1] Getting acquainted with the source code doesn't have to be that hard, either. It is a bit of a problem in less-organized projects, but still better than a closed-source base. As a developer, I think this is something more people should be used to. That is, rolling their own solutions when they don't get what they want.