Twice a year would be cool. Winning a TSL would still be much rarer than winning a GSL.
The main reason I say wait a while is because it sounds like the behind the scenes guys need a break. Let them have their rest so that when they come back TSL 4 will be every bit as perfect as TSL 3 was.
I don't know if it is some intrinsic property of TSL or if Hot bid and R1ch really are wizards, but it seems like TSL has no choice but to be completely epic. It goes without saying the ro32 will be excellent. You know the finals will blow your mind. I expect the other leagues are studying TSL very hard to figure out what the secret ingredient is.
id rather have a prize pool be big for each year instead of chump change 3x a year. and the hype is awesome for esports because when u make people wait, they want it more!!!!
I think that once every six months or so would make it really good. The good thing about TSL is that it doesn't happen all the time, so it is able to get a good hype behind it.