Regarding Catalan and Hebrew Wikipedia, the other Amir said it well, I
don't think I have much to add beside the fact that I have personally seen them finding major issues before they hit all Wikipedia languages many times, more than I can count.
Apologies if I didn't make myself clear, but it seems I didn't given both Amir's comments. I am very happy that we have these, and my question was *not *why do we have them, but rather* why do we only have 2*. I want more of them and every time I've asked why we don't have more, I've been told it's a community decision and that seems odd to me.
Anyone is welcome to correct me if I'm wrong, but I'm quite sure that there is no community decision to have *only* two. I suggested these two back then, because I felt that it is *enough*, I can read these two languages and I thought these two communities would not be opposed to it, and I even happened to be right. (Hebrew also represents RTL languages well.)
So there is probably no blocker to have more than two. You should probably ask the relevant wikis similarly to how I did back then, get an agreement from them and from Rel. Eng. and SRE, and that's it.
How did I ask them? I just raised it myself with my personal account in the Village pumps, there were a few positive responses, and that was it, it worked and no one complained. But don't take my word for it :) You can do the same or maybe you can go through a more formal process. Up to you. Which languages to pick? - I'm also not sure. Maybe some wikis that represent special features, like the Growth extensions, or language converter, etc. Also up to you.