I think the new ones Linkus have been working on looks great, and I plan on using those in Castle Town myself so if he doesn't end up finishing them, I'll have a go at it eventually. I'm all for having both variants in the set though, and it's not like we can't have alternatice, non-comboed tiles in the tilespages for those who wants to mix things up a little. I believe there's already at least one set of mountains that aren't comboed for example, which probably never will be either, but they're there for those that wants to use them. Those who don't need it can use the extra space for other stuff.
Also, I've seen a couple of people mentioning the lack of background tiles for mountain scenes and so on. That is true, at the moment there is only the titlescreen from tHP (which I believe you can find in the extras folder), but it uses a lot of colors so it's not completely workable within normal palettes. Unless it has been changed since I last looked at it. But most tilesets don't actually have these kinds of background tiles to begin with, which is why we've got a great database full of stuff to use. I know for a fact that Linkus has a pretty cool mountain backdrop in the database, for example, and with some recoloring you could probably make it work within Firebird pretty nicely. Just a tip.
That's not to say there won't be anything like it in the complete set, there might very well be, but for now you do have some alternatives outside the tileset.