A few quick thoughts (and possible spoilers, if you are not familiar with the play):
I don't know what play Kevin Spacey is acting in, but it certainly isn't A MOON FOR THE MISBEGOTTEN. His overwrought, histrionic gestures fall somewhere between drawing room farce and the Marx Brothers, and it throws off the entire focus of the play. Lines that are TRAGIC are getting laughs. That's just wrong.
On the other hand, Eve Best is giving the performance of the season. For the first time ever (including Cherry Jones and Colleen Dewhurst in the film), I truly and wholeheartedly believed that Josie thought she could redeem Tyrone with her love. Every move she made had a reason behind it; there is nothing at all false about her performance. This is more than just acting; she's LIVING the character on stage, and it's fascinating. I just wish she had a capable co-star to match her step for step.
Colm Meaney is wonderful. I'd expect a Tony nomination, and he could be a real contender.
Even with names like Lansbury, Seldes and Redgrave in the mix, I really think Best has the Tony in the bag.
Finally: While there really is nothing technically wrong with Howard Davies' production, there is also no real kinetic spark. That's a problem.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body