Fix enroute for EVO 4G screen sensitivity concern, problem with glass separation is minor1
As for the glass separation issue, the same source says that HTC is calling the problem "minor" and outside of a little "give" when you touch the screen, there should be nothing serious that will happen to your phone. The manufacturer says it will keep an eye on the situation, but states that future units should benefit from some assembly changes it has made. What if your phone already has the separation problem? Why tempt fate. Return it and ask for a new unit-preferably one that was made with the previously mentioned "assembly changes".
HTC EVO 4G Specifications | Review