I would like to suggest mod support, so rather than having to deal with a black screen from deleting the meta-inf, we can actually play minecraft with mods. Another idea, take the mods that have been made, and add them INTO minecraft, just so we, the players, don't have to deal with installing the mods. I think alot of people will support this.
I think a lot of people will say "this goes in mods part of the forum."
Heck, the texture pack selection screen is titled "Mods and Texture Packs"