Flight1 has released a new scenery design tool, Airport Facilitator X. I have not (yet) tried this new tool, but looking at the info and pictures they provide it seems to extend AFCAD. Of course it is always good to build on such a nice tool.
The tools works with both Fs2004 and FsX, and for FsX they have added support for some of the new features like blast fences and jetways. Another nice feature seems that it can link with FS to show you what you are doing in the sim while you are making the changes. I can imagine some occasions that that would be useful.
On the other hand, it does not seem to add all the features that were missing in AFCAD to make it a really perfect tool. For example I don’t see placing scenery objects on the feature list. (I can understand they did not put it in, as they have their Instant Scenery tool for that). And their are more XML commands that BGLComp provides, but AFCAD does not support.
As you might know there are also some freeware tools being developed at the moment that are working on similar functionality. The two that come to my mind right away are FSXPlanner and ADE. In general I think these are trying to offer a bigger scope of features, so that you can design your entire airport with one tool. But on the other hand they are still under development and might contain some bugs. So for a designer that just wants to make some adjustments for which he (or she) used AFCAD before the new Airport Facilitator X tool looks like a good (and easy) choice. And for those that want more, it is good to see that there are some alternative around. Some competition is always good I think.