You can only build hype for so long until it dies off and people grab something else. Droid 2, Droid X, vibrant, captivate, iphone 4.... the list goes on and on and every day the epic doesn't get a release date I'm willing to bet Samsung/Sprint lose customers.
I honestly had 0 motivation to look at the Droid 2. Now that the Epic would be lucky to come before the end of August I'm thinking that jumping carriers wouldn't be so bad. At the very least I know I'll go try it out in store where as if I owned an Epic or knew it was coming within a few days I wouldn't even have thought about it.
Aug 20 (our best guess) is a very late launch in my mind. Its especially late since its coming with 2.1 and the Droid 2 will come with 2.2.