Hulk Struggling?

One commenter at MR caught my attention. They noted already Wall-E has surpassed Hulk, even though Hulk's been out four weeks. Sure enough, that is the case. This is probably not too good a news for Marvel Studios. Revenues fell 60% after the first weekend, another 57% after the second, and then almost 50% this last weekend. It's still got $25 million just to break even. It's still early, but at the same time, with so many more superhero films this summer, can it realistically be a blockbuster this summer? I've said several times that I worry that so many superhero films are simply starting to cannibalize one another, and I wonder if Hulk isn't an example of this.