Now that we've passed the Drupal 8 feature freeze, it's a good moment to present some statistics of Drupal core code base evolution.
All the charts are here together in this infographic:

Update. Just to clarify
Drupal 8 core has experienced big changes in the file structure, probably the biggest ones in all Drupal's history, so I wanted to help to assimilate this change in a visual way.
But clearly isn't it enough to understand the full picture of Drupal 8 core changes, and I hope the graphs are not misleading. Please, I encourage you reading Dries, Crell, catch and the other initiative owners to know more about the conceptual and underlying architectural changes of Drupal 8.

Update2
Tim Plunkett ‏points me via Twitter to this issue: http://drupal.org/node/1475510 . If this issue gets fixed, then Composer (tool for project dependency management) will take care of downloading the Symfony Components and we won't need them in the vendor folder.

Still, I would consider those components part of Drupal core, but what do you think? Should the vendor subdirectory be considered part of Drupal core or not?

Update3
For the sake of completeness I added in the first chart a variant of Drupal 8 core without the "vendor" subdirectory.