In five years? Either dead or with very little technical changes, based upon how much income it brings in to the founders. As for members, the typical coming and going.
If it survives another 10 years? There will have been a change in ownership somewhere along the way. It will bring on a new look and feel that fits in with technological changes over time. As for members, most will have left the site, and a few possibly figuratively.
In 20 years? I have no clue.