This was discussed in the beta thread but I thought I would break it out here for more visability.
what have they changed? First and foremost they updated the previously horrible library management system. As much as I loved DipTrace, I HATED the LMS; I hated it with a passion. It has been no secret that it was one of the biggest letdowns in DipTrace. You could work with it (mostly) but it wasn't pleasant or intuitive. Novarm has long admitted the system was broken and they weren't happy with it. More recently, they mentioned that a complete rewrite was in the works and it now appears to have gone live. The library management system has finally been completely revised. Libraries are now broken into groups, separating the user libraries from the standard included ones. This appears to allow them to automatically add all libraries created on the computer. You can still add/remove libraries manually via Library Setup if you so desire.
I seem to remember this at least partly occurring in 2.3.x versions, but the standard libraries themselves have been revised. There are now libraries of common parts such as headers, connectors, caps, etc. Instead of the older system which only had everything broken down by vendor name.
While selecting components in the schematic phase is MUCH easier now. Showing both the schematic symbol and the pattern in large easy to see form:
Search of the libraries has been made much more prevalent and logical. Gone are the unintuitive concepts of active library, non-active library, etc. It is now called Filter and its kinda like the old search on steroids. It's easily available from the library menu on the side.You can search a single library, a group, all libraries. You can also search using one or MORE criteria by hitting the + button.
Quite honestly, these changes to the LMS have made working in DipTrace even more fluid. Making the system feel much more unified and intuitive overall. The LMS doesn't feel nearly as cumbersome and awkward.
Another area that saw some changes is 3D modeling. 3D modeling now supports the much more common STEPS/IGS files for 3D models. This makes finding 3D models for your boards MUCH easier. Additionally, the most recent 3D model file has a bunch of new models added (on top of any that you import yourself)
The Arduino Nano in this board is an IGS file I found online. The 3D model actually saved me from a huge blunder. On an initial design of this board, I actually had the nano rotated 90 degrees which meant that the USB port was rendered inaccessible by the pi-filter capacitors.
Being as this is a 2.3 to 2.4 update (and not to 3.0) most of the other stuff is behind the scenes and bug fixes. Such as switching to a new version of Delphi which supposedly will allow a native OSX version in the future(no more WINE). My guess is when that happens we will see version 3.0. They also added full unicode support.
A changelog is available
here.