1. An option to play offline, like the vanilla launcher.
2. Optifine installed on all modpacks.
Before I discovered FTB, I used to play Tekkit, which had both of these. They are the only things I lost when I switched to FTB and I really miss them. I have a painfully slow internet connection and sometimes no connection at all, so the offline thing is the REALLY important to me. I also realize that my other suggestion isn't really to do with the launcher design, but it's something else I really want added.
2. Optifine installed on all modpacks.
Before I discovered FTB, I used to play Tekkit, which had both of these. They are the only things I lost when I switched to FTB and I really miss them. I have a painfully slow internet connection and sometimes no connection at all, so the offline thing is the REALLY important to me. I also realize that my other suggestion isn't really to do with the launcher design, but it's something else I really want added.