There are several modpack launchers available now (Tekkit, FTB, ATLauncher, etc...), but mod authors get butthurt when you don't visit their ad infested download links and there is infighting between the different groups.

Minecraft's mod scene is a mess. Whatever Mojang's efforts were to make the game mod friendly have never seen the light of day. It's really sad because mod authors have done some really amazing stuff with the engine, but because every update breaks everything its too hard to keep most of the running for more than a version or two.