Champ masteries should not be implemented in ranked. Ever.
These take away from focus on winning with the team, and shift focus towards getting yourself some points on a champ.
I can see horrible choices made in ranked games champ select and gameplay due to this.
Seeing as spamming a champ will eventually get you to "master" level on it, they are pointless anyways.
Riot, please keep this feature out of ranked.