How many coders have they got working for them at the moment? Do you know?
I really have no idea. And I don't know how much I can tell you exactly about it (because of my NDA with Amiga).
I think I _can_ tell you the SDA list is very active. I estimate about two dozen of people are actively using the SDA-lists (with actual development-related discussions), but every now and then someone I've never seen on that list before pops up with a completed application or beta release for us to look at, meaning more people are developing then I can see on that list. Some are mostly in listening mode on that list, while working on their own applications (not just games). On top of that there are also developers who didn't sign an SDA and are therefore only on the other developer-lists, which I don't track as accurately as the SDA-list. The SDA-list is also more active than Tao's open Developers-list which I'm also subscribed to.
All in all it is very hard to say for me. If we go for just Amiga-Anywhere developers (not other intent-developers) I'd say it will most certainly not be thousands and I don't think hundreds either. Although it might very well be a bit over 100. Most of them are only part-time AA-developers though, they usually have a full-time job next to it, untill they are able to earn enough with Amiga-Anywhere to go there full-time (I would love to do so).
As I said.. hard for me to say. The only ones who actually know are the people at Amiga Inc.