It's not '>=' it's '>>=' the Haskell monad binding operator.
(I also agree, that logo is pure awesomeness)
I know, but most people don't. Your logo can't be designed only for people who know the language.
Most people think >λ= means "greater than" "lambda" "equals", not a clever play on monad binding op and lambda...
I agree that simplicity is very important, I like this one best: http://haskell.org/sitewiki/images/2/21/Haskell-apankrat.png