Just called and tried to get some clarification on the situation. I asked your question about WL, and from her reply, it seems they are concentrating right now with interview invites still on the R3 people, but may move to WL people later. She said it is still early in the process at this point.
If you look at previous year's data from business week blog, the majority of the invites went out the first week of May, IF the blog is a good sample of the population. A few went out before Admit weekend. But this week towards the end and early next week would be when I expect some action.
Best of luck to all of you. With so many awesome profiles, it basically comes down to that. =P