Heh, you're quite right about that!
We don't have a public list -- we've noticed that when companies do that, there's a lot of pressure to work specifically on the things at the top of the list, which isn't necessarily the most important thing from a systems perspective, or the right order to do things.
This is because there are also non-obvious connections between things; for example, in order to get WebSockets working sensibly, it would make sense for us to sort out what we call "long-running tasks" first -- that is, come up with a system where people could start Python processes that would run forever, or rather, be restarted if and when they crashed. That's the best way we can see to supporting WebSocket servers like Tornado. But it's also a really useful thing in itself, and it's something that people are asking for independently. Now we can add to that the fact that for obscure internal architectural reasons, getting long-running tasks working is best achieved by starting with some changes that will allow us to provide different system images for different users, so that new users get (for example) Django 1.10 for all versions of Python, while existing users keep the old versions so that their code doesn't break.
If we had a public list, it might have WebSockets at the top, then a bunch of other stuff, then long-running tasks, then right down the bottom might be the different system images for different users. So when we said "we're working on the different system images" thing then we'd look like we were ignoring what everyone wanted, and people would get upset. If this were a one-off then we could probably explain it and everyone would be happy, but if it kept happening (which is likely) then it would mean we'd spend a lot of time explaining and less time coding the stuff people want :-)
However, all that said (and apologies for the lengthy post!), and to answer your main question... there are some broad categories of things that can be treated as competitors for WebSockets. A few things that come to mind:
- Education and collaboration features
- Hosted MongoDB, REDIS, and memcached
- Better support for mobile devices/tablets