I am trying not to get too worked up about this particular rumor. While I have pre-ordered one and am anxious to receive it, it does no good to worry about whether it "might" be delayed. First, there were a number of qualifiers in the rumor itself. The idea that it will be delayed until June is apparently being voiced by some folks, but not "announced" by Canon (at least not yet).
I believe that Canon has every incentive to get the camera to its customers as soon as possible, but as others have said, not if that means releasing it with known problems.
If it is delayed, I will be ticked, but will look forward to getting it when its ready for primetime.