I had a launch day phone, build 002, don't know the build date. After a month (just a day or two over) the charger wouldn't read well. It was definitely loose, and I had to make sure the phone was laying down in a way where the charger wouldn't move after I plugged it in. Brought it back to Radio Shack with no problems (except waiting for a replacement unit). Never dropped the phone or didn't anything to break the port, and one month's use shouldn't have degraded the integrity of the port that quickly.
However, I don't think this is an HTC issue, I'm sure this happens to all phones, I haven't heard this being a widespread issue, so I'm sure we just got unlucky and got a device with a bad connection port.