Captainhook told me it's impossible to switch from Scrypt/PoW to X11/PoS but i proposed a plan to make brand new iCoin PoW/PoS and current iCoin holders can exchange old Scrypt iCoin to X11 iCoin.
Yes that would probably be the best solution. I believe Particle is going to do something similar, have an exodus address where you send your old coins and the system sends you corresponding amount of the new coin:
https://bitcointalk.org/index.php?topic=392804.msg6865589#msg6865589A new fresh start for iCoin would attract more attention and lots of miners wanting to mine the launch. New people could mine low diff coins and old holders would be awarded coins according to their old iCoin holdings.