The most exciting move in Acquia for me so far just happened a few days ago. We rolled out what was called "Big tent" internally, and means much wider support for all Drupal 6 sites. As Dries points out in his blog post, we used to support our Acquia Drupal distribution via forums, tickets and phone support. However, we found that virtually all sites will use other modules, custom code and themes, tweaks to existing code.
Well, although I was the first employee at Acquia, I somehow managed to keep myself out of actually using the product on my own blog up until now. While I know we have a great product, built up from superb community contributed Drupal modules tested to work together, distributed under the GPL, I did not find the time to actually migrate my personal blog to this distribution of Drupal.
One of the factors causing this was that I actually ran Drupal 5. Wow, another shocking revelation about the Drupal 6 maintainer! Especially considering that I only run the contributed modules Pathauto, Mollom and Tagadelic, and these were ready for Drupal 6 already. In fact, I've tried to upgrade to Drupal 6 already, and in preparation to that, I've got rid of some contrib modules, replacing Flickr syndicated images with Flickr's own image script display for example, thus avoiding using Drupal modules for that. This helped me prepare for an easier Drupal 6 upgrade a few months ago. Except I never got around to actually doing it.
Being a maintainer of this simple blog, as a user of the above mentioned three contributed modules, the Drupal 6 based Acquia Drupal upgrade was the most logical step at this point. I've made a backup of my source code and uploaded files, as well as the database. Did a test upgrade on my local machine and it went great right from Drupal 5 to Acquia Drupal, even picking up the moved contributed modules. It was a piece of cake.
On the test upgrade, I've even played around with using the built-in Acquia Marina theme, and found it great, so switched to that from the Alek 2.0 theme. Because these three modules are included with Acquia Drupal, I could just use it for my blog from now. Additionally to keeping what was in already, the Drupal 6 upgrade allowed me to track updates to my modules, add support for OpenID, and so on.
If you are still considering upgrading to Drupal 6, Views 2 being out and Acquia Drupal soon upgrading to this stable release, it is a great time to switch. Drupal 6 is well tested in the field, as Dries shared it on the last Lullabot podcast, five hundred active sites are deployed daily based on Drupal 6. My site is just one of them for today.