When the game goes to level 50 i believe that the game will see an increase in players upto level 50; however, the content at level 50 may see a drop in player numbers because the cost of subscription is no longer worth paying when there is so much free content.
I myself will probably not bother to buy subscription again unless there is a change. If the price of subscription is lowered from the £8.99 that i pay a month to a more reasonable level.
What does everyone elts think; will you want to pay the current subscription cost after this update?
The way i see it is that if the subscription model is kept the same, your money is keeping the servers open for the F2P people to play.
This is all over simplified and holes will probably appear in it left right and centre but i hope you get the jist of it.