These items come out May 12th. As they are not out yet, I do not know exact sizes, insides of bags, or which ten Pokemon are on those ten blind-packaged pins... that we know any at all we can thank Junichi Masuda for, as the site just says "No spoilers", basically. I can say I am pretty sure Munna was one of the others, no idea on the rest. Knowing Pokemon Center it's probably all of the least popular ones on those we cannot see :P
Don't forget Mini Dolls and Muskedeer dolls are also still available and so are these cute Keldeo cups newly added :D
Thank you, citizens!