ISS till 2028?

On Mar 12, 2:42*am, Pat Flannery wrote:
Life extension concepts are being discussed:http://spaceflightnow.com/news/n1003/11station/
...one problem in doing this is that, like Mir, you would then be using
equipment that was never rated for anywhere this long of orbital
lifetime, so you can expect a lot of failures as things wear out.

Pat

How could you make ISS "upgradable"? After all, it seems a shame to
de-orbit it just when it gets finished and it has yet to accomplish
anything.