I have calculated and published numbers previously using country specific success rate calculations - that does vary things from the regional ones I used above - the difference isn't that significant.
Agreed on DV2015. If my theory holds true I can't see any reason why DV2015 would need a selectee number similar to this year. So - if we see 140k again - I will eat my hat.
There is a major change in that Nigeria is ineligible this year - I'm not sure how that will affect things although as they are over 15% of the entrants globally it is bound to cause some differences (at least in Africa region).