Optimist opinion - he'll be back late March/ early April, in time to be ready for a 10-15 MPG contribution in the playoffs (which is all they ever wanted him for anyway).
Pessimist opinion - he's a bust, done for this year, never get back to form, won't be a contributor next year either.
Pragmatic opinion - He'll be healed from the surgery in 8 weeks with enough time to be in shape and in rotation for the playoffs if he is determined to do so. His history this year tells us, and knee issues like his support the likelihood, that he'll experience pain at some point after the surgery (sooner or later). BUT, we have no way of knowing the extent to which the surgery will reduce the short-term likelihood of debilitating pain or restriction of movement. No one here could possibly know, or credibly speculate the outcome of the surgery. Likewise, no one here can credibly speculate JO's determination to return (though many here seem to think they know him well enough to know his heart and work ethic -- baloney -- no one here knows him). There is as good a chance as not that he will be able to provide some decent minutes given the playoff schedule.
Pessimistic opinions seem to dominate here so far.
Regarding the MLE: the only importnace of the $$ spent relates to who would have been here instead and what contribution that person would have made. This, we have absolutely no way of knowing. BUT, I'll say with pretty good certainty that we wouldn't be much better than 37-12 with the #2 record in the NBA.