Attended the information session a couple of hours back. Here are the answers to the questions a few people asked:
1.) Applications are segregated geographically. These are given to separate app readers (going forward these readers will specialize in a particular region). Also, the selection (for an interview) of a candidate may happen as soon as the reader reads the application or after all the apps have been read. So, you may expect not a lot of difference (in days) between invites for candidates from the same country.
2.) R1=R2>R3>R4 in terms of both scholarships and acceptance ease (still not sure about acceptance rates - she did not have the numbers)
3.) You may be waitlisted without an interview. You are then compared with the subsequent pool.
4.) The adcom have just begun or will be beginning to read applications. So, in all probability the invites have not gone out yet.
There were only 20 of us. So it was a nice little session with a lot of interaction.
We discussed almost everything under the roof. So if you have any specific questions shoot out, and I may be able to answer those.
Best of luck to the folks who are waiting.
Cheers!