Don't integrated headsets wear out, ruining the frame? I came upon this marvelous explanation of headset types.

However, this got me wondering. Isn't the role of the headset cups similar to that of the derauler hanged - to not waste the frame as soon as some wear-outable components ends it's life? How do frames with integrated headsets survive more than several years?


from forums.mtbr.com
Here's an excerpt from Chris King about headset types:


  What is an “Integrated” headset?
  
  It is a bicycle frame, fork and bearing system designed to eliminate the humble headset cup. To integrate
  means to combine and hopefully to simplify. What has been “integrated” by the integrated headset? The bearings
  now rest inside the frame instead of inside pressed-in cups. All of this trouble and confusion is to remove two 12
  gram headset cups from the front of your bicycle. True, an integrated headset can give the bike a nice, smooth
  looking front end, but the consequences of this change to your bicycle are significant. 
  
  Simply put, the performance
  and lifetime that you expect from your new bicycle will be reduced, most severely in aluminum mountain bikes. All
  bicycle frames that use integrated headsets will ultimately have substantial performance and reliability problems
  due to the inherent flaws in this design. The largest flaw is a bearing system that does not positively attach the
  bearing to the frame, leaving the bearing to “float” resulting in wear and impact damage to the frame. 
  
  As an
  additional complication, each manufacturer seems to be doing their own thing, with no real standardization to date.
  As a result, there are multiple bearing types and sizes (some of which have been discontinued with no replacement
  options) and the frame builders and bearing makers are not all working from the same drawings. Lack of
  standardization is a bad thing for everyone. It means that you may not be able to get replacement headset bearings
  for your bike, and you
  will
  need them.


So, to answer your question, yes, an integrated headset will eventually wear out, but that service time is dependent on riding type, style, number of hours, and quality/material of the frame.

You can read more about all three types: Integrated Headsets Explained