I don't think he deserves to be sacked, nor do I expect him to be anytime soon. He has built this star studded squad, so if this season is a failure, then the failure is firmly on him. I feel he's been afforded a very fair amount of time and resources to rebuild, and failure this season, would warrant the sack. I hope it doesn't end like that, and he can leave on his own terms. However, if things go really tits up over the next 12 games, he has to go.
I'm not really a fan of us sacking managers mid-season, and I have no idea what the data is like, in regards to whether it usually works or not. We saw with Chelsea it worked wonders and the same with us when we sacked Jose for Ole. Obviously, there will be some kind of new manager bounce, but it's about proper sustainability and not a short term bounce. Our next appointment needs to be so well thought out, and the fear is if we sack Ole before the end of the season, we will make another rash, impulsive decision that sets us back again. On the flip side, if we have a really bad next 2 months, the Boards hand might be forced.