My point is that Apple is smart enough to realize that once the pictures were released that they would be all over the place, and that getting the lawyers and such involved would only alienate a core part of their market, and provide confirmation that the device was real and not some clever fake or something.

The tech blog followers may not be the biggest number, but they are extremely vocal and their support of a device/format will go a long ways towards determining its success. I think Apple would probably realize that it's better to take the good that they can get from the situation than it would be to turn hostile against the very people that they need to like their device.

So while they surely could sue the hell out of Gizmodo and win, there's a very real possibility that it would cause a serious backlash against them that wouldn't be worth what small amount of money they would actually get in any settlement or judgment against a blog.

Edit: I say small amount there at the end, because let's be realistic....the judgment might be huge, but the people running these blogs are not rich enough to pay it by any stretch of the imagination.