Well I baby my phone and while there hasn't been an instance where I pressed the button and it didn't respond YET (keyword here) the fact that I'm seeing noticeable wear over the course of 3 WEEKS, is definitely reason enough to be concerned about a device you intend to use over 2 YEARS.
Sure to some people this doesn't mean much. But the fact that there's already 2 people who claim the buttons are getting recessed from much use, and that from day 1 every Droid X has wiggling buttons, is not good signs for those of us who like to keep our devices mint.
Not to mention I have serious OCD when it comes to things like this, and to have 1 (1/2 if you must) of my buttons recessed lower than the rest is quite annoying. It sits in the back of my mind, and just looking at it I know there's a discrepancy. And it drives me mad