I get the point of what the OP is saying BUT
Why the heck would they let you, and their investors, in on inside information? If they are transparent, and say oh it is going to be a month, they risk losing pre-orders to those that do not want to wait AND to any competing phones that may be released. If they string you along, more people than not will stay with the original purchase out of hope and out of "this is my first choice".
No doubt some people will cancel the preorders anyway, but it is a trickle compared to a possible onslaught. Just an example, it they lose 50% of pre-orders because of announcing the delay, they may only lose 30% by stringing you along. They save 20% of the orders this way.
Sprint really cannot say anything because this is not their issue. they are just the distributor. here is the conversation
S: Hey are we good with the EVO launch?
HTC: um...well you know that lawsuit, customs won't let them in the country so they are stuck on the docks
S: well that is bad, what are you doing about it?
HTC: we are doing everything we can. Working with customs and we have our lawyers on it.
S: Well how long?
HTC: we just don't know at this point. We are working as fast as we can.
S: ok you will let us know when everything is worked out right?
HTC: yep, you will know as soon as we do.
HTC owes you nothing except a phone that you paid for. THey couldnt hold up their end on time, but you have the freedom to bail out.
This is the reality of it all. In a "hello kitty world" they would be totally up front and let us know everything. This is the business world and it makes better sense to say nothing