Being that this is still part of Apple's first steps into the cellular market, there are bound to be mistakes, but it's only been a few weeks since MacWorld, and they should have had a better idea about when the SDK would be ready at that point.
Unfortunately, it seems that Apple has learned that no matter what mistakes they make with their consumers, they know that we will sit here and take it. The only time that was not the case was when the price dropped 2 months after hitting the market. Everyone and their grandmother knew how wrong that was.
As for the rest, well, there is nothing we can do except continue to jailbreak and enjoy 3rd party apps that are unapproved by Apple.
Why are you so surprised it's delayed? I kind of laughed every time I read a post that simply assumes a date is written in stone. I'm just as eager for SDK as the next person; I just know better than to assume anything will ever be released when the so-called consensus says it will be... Having followed Apple for the past year (since I migrated entirely to Mac) I've learned they aren't much better than any other company when it comes to releases.
A delay I wouldn't be so surprised of. It wouldn't bother me either. But June, I don't think so. Steve clearly stated during the Keynote that the SDK would be arriving in Late February. June is a long way off.