Yesterday, I had the pleasure of doing the MR with Tom (highitinerary). Neither of us had done the MR before and we hadn't met each other until yesterday morning at the Portal trailhead (at 4 a.m.).
Overall, the MR trail is quite evident. The creeks are running a little high right now so waterproof shoes or boots are recommended. You can make it up the chute without going on snow (which is soft and mushy) or talus (except for a few brief moments). There are a few patches of ice after the notch, but they can be easily avoided.
The weather on the summit was as good as it gets on Whitney.
The Main Trail is clear, even the cables.
Thanks to Tom for his hiking companionship and help.
Special thanks to Doug, who gave lots of advise prior to the trip. If you ever do the MR for the first time, have Doug show you his aerial photos of the chute and the north face.