...rereading a Star Wars comic book, or graphic novel.
Make all planets have a level 50/55 option to players, and even have an option to replay the entire Class storyline at 50/55, with the staged, or even long time reward to achieve a playable third companion, with maybe the option after this, to unlock a Hard Mode/Nightmare option of 50/55 planets, quests and story, for further rewards that will give PvE players, plenty to go after.
I doubt this will be immediate, and has likely been offered as a suggestion before, but it would be nice to see a reason to replay content, just like above said: a favorite comic that has been reread so much, the staples cant hold the pages in anymore, or the pages, have pulled away from the glue backing.
There'd still be planet choice options for going to the base lower version levels of these planets, for players to help lowbie friends with base content, so being at 50/55 wouldn't lock you out from helping, for social content reasons.
I'm posting this, from the fact I beat the Emperor last night, on my JK, and felt I had a lot of fun doing the storyline, but felt a tic lacking that I had to do the majority, feeling I need to use Doc more, over the other companions, and further, that the story was well crafted out, and warranted the aboility to replay, at a higher level content. This in addition to feeling out of place now, on low level planets. (Feels a bit dumb actually, to walk past a tight mob pack, of low level mobs, w/o aggroing. But that's just moi.)
Obviously there would be issues, such as flooding the GTN with even more items, and an inflation of credits from extra content running, and other stuff I'm not thinking of, but I still think (for my part,) that the PvE content could do with a new polish coat, so to speak.