Pokemon GO launches today. Seems they are timing it via region, starting in Australia, New Zealand and Japan and moving west.
The game will start with the original 150. Mew and any legendary they are determining how to implement, most likely through special milestone events. Likely we'll see the following generations starting next year so people have time to collect the 150 without feeling overwhelmed.
Kotaku also has the breakdown on the microtransations. I'll admit, that 20 pokeballs for 100 coins which costs 99 cents isn't too bad a deal there, though I am not a big fan of microtransactions to begin with. But we know people will buy them. But then they have to make money off this thing to make the money back and get more pokemon in the game. Seems there will be other ways to get items but the quickest way to stock up is forking over some cash.
http://kotaku.com/here-are-pokemon-gos-microtransactions-1783182493