so, we've been talking about stopping support
Yes, please! SDL1 is past its useful lifespan and was the cause of various weird window problems that just went away with SDL2.
I believe package tags can indicate that a package is not compatible with Python 2 but for good measure we should sabotage setup.py so that it refuses to do anything under Python 2.
My big/growing bugbear is with pygame.mixer/SDL_mixer. I'm really glad you've fixed the MP3 support in 2.0.2dev4 but I don't think the underlying library is good at all - no procedural sounds, spatial audio, HRTFs, and sound buffers can't have variable formats (you can't supply a mono sound buffer when the mixer is set to stereo).
If we're thinking of big, big changes, maybe we could build a laundry list of them and jump to PyGame 3.0?