Shisui's Mangekyou power (Kotoamatsukami) is only usable once every 10 years unless the user also has the 1st Hokage's cells(which lowers the reuse time to, like, a day).
This was stated before by Danzou. And now restated by Itachi.
I was just saying how, since the Mangekyou power is unusable for the next 10 years, fixing Kakashi's eyesight is the best use that eye has now. Unless you're going to give it to someone who has the 1st's Cells, like Yamato.
On a completely unrelated note, Shusui's Mangekyou is the first one they've shown that's 4 sided instead of 3.
I'm guessing that for whatever reason, zombie eyes are no good for transplanting. Otherwise Kabuto would have just taken Zombie Itachi's eyes.
The thing I'm hoping happens now that Itachi is free is, if he doesn't have to sacrifice himself to defeat Nagato, then I want him to come into contact with Sasuke, and tell him what an R-tard he is.