Is anyone still working on this?
A brief history...
1. Twitch thought of the idea, and started on it.
2. Kinnik helped him out and they got a lot done.
3. Twitch realized how much work it would be, and stopped.
4. People lost interest.
5. Some random guy came along and said that he's been working on one, then disappeared mysteriously.
6. Thespis tried to do it, but had lots of trouble.
7. Twitch shared his source code.
8. Kinnik and Thespis started to work on it.
9. Twitch considered recreating Spelunky in C++, to then possibly include multiplayer and/or port to DS.
To answer your question, kind of.