I think what it is going to come down to is what Google ultimately wants the "Google Phone" to be marketed. If Google truly wants this to be the Google Phone, then it is quite possible we will see them market it directly as an unlocked device running stock android 2.1. As stated above, Google most certainly has enough cash sitting around to subsidize the phone down to make it more attractive to consumers.
However, I don't know how realistic this is at this point. We still don't know if this is truly the case, or if this is just another dev phone that will ultimately be on T-Mobile or some other U.S. carrier. I am still sticking to the point that, IMHO, this is not a true "Google Phone" no matter how you look at it. As it stands right now, it's an HTC phone running stock Android 2.1, and until that changes, I don't see how this is all that different than a Google Experience device.