In previous years around 105k people were selected. Many people (around 50%) don't take up the opportunity (because they don't qualify, or their situation has changed), and some people get rejected during processing (not many - I've seen numbers around 7 or 8% of those that apply). There are also some that won't get an opportunity to be processed because their country has too many winners and hits the 7% single country limit and various other reasons that selectees don't get visas.
In previous years the 105k has sometimes failed to fill all the available visas (50k after taking the 5k for Nacara). Don't forget the selectees also have dependents that have to fit into the 50k - the average is 1.6 visas for each application - although by country, some countries vastly exceed that number. It is also true that some years have had second drawings (of around 10k more selectees) to try to make sure the quota will be filled.
There has been lots of discussion/speculation why there is a 20% increase this year (from 105k to 125k). I personally believe that speculation about the immigration bill and failures to fill the quota prompted someone to select MORE THAN enough selectees the first time round. I don't believe anything else will affect the way those are processed (such as processing resources, tighter enforcement of rules and so on) - so the speed of progress will probably be the same. To me that also means the very highest numbers are more likely to miss out in 2014, and to push back the time when all countries go current.
However this is all just my theory - I might be completely wrong - after all - I only got interested in this whole process around about May 1 this year....