Hi, been using diff CMS and also developing a few on my own (perl based). About Open Source, I've been using Drupal a lot and quite happy with it. There is always transition challenges, some didn't like the 6 to 7 jump and I agree, still I adapted and took on Drupal 7.
But now they are changing most of the code like making a new CMS (almost) and they are mixing a lot of Drupal with Symfony. Worried? perhaps we should. I've taken a look at it and didn't like it. Share your opinions Drupal Users.