Acceleo 3.1.0 is due June, 22 2011 along with Eclipse Indigo ... seems far, but not as far away as we sometimes hope for with all the features we'd like to add in our products.
Because of this, we've already started implementing some of the (many) improvements we'd like to make in the Acceleo editor : support for template, query and module documentation, support for more markers to display feedback to the user (information, warning, "overriding" link...), support for tasks in the template (TODO, FIXME, ...), improvement of the oultine, feedback on the non-printable characters that will be generated ...
Stephane Begaudeau is reponsible for most of these first additions, you can find a list, detailed explanations and screenshots in this great post.
Most of these improvements have already found their way in the source code and will be available in the 3.1M1 release of Acceleo tomorrow, care to test? Or are there features you would like to see in the Acceleo module editor? Don't hesitate to take part in the discussions, raise bugs or provide feedback on either bugzilla or forum :).