Robert says that we can already do this, with some effort. Those making really huge Drupal sites should really be prepared to put some effort in. Drupal will rarely fall out of my downloads folder and onto a production server. Save patches like these for D7 and move on.
What was the compelling reason for this to go in post freeze?
On the last project that I worked with Robert on, the advcache and memcache projects were used. It was a very complex site, and thus the caching solution was fairly complex as far as that goes. As Drupal becomes the standard for large dynamic media websites, any place that we can add performance is going to allow Drupal to be used by even more large complex sites and thus the entire project will continue to expand and get more large commercial companies funding the growth which is good for everyone. If we have a technology like node caching that is only used on 3 major Drupal sites via patches, with each implementation custom or slightly different, it will certainly not be any more stable for Drupal 7 than it is now. If we have hundreds or thousands of people who just have to click a radio button or add an option to settings.php to turn on node caching and label it as experimental, then we can begin to stabilize this great performance boosting technology. If it doesn't work with your particular set of modules, fine, turn it off and no harm done. I believe that since nodes are the crux of the Drupal system, releasing Drupal 6 without this technology is a real shame since there are so many great performance options that will be available for Drupal 6. Steve Rude