Actually, a lot is in the planning.
Here's one article.
Robotic satellite repair
I read another recently, too, which would utilize some sexy propulsion system and could hit L2 easily.
It would seem "they", all of "them", would have to design the things so as to be able to be repaired and refueled easily. I would suspect modular everything, with things like hydraulic quick-connects. Grab it, unplug, plug, and throw away.
On the other hand, there are five fingers. And bright people who know the technology are figuring it out.
Wahoo!