During the last weeks a lot of work was done to remove the old DataConnection implementations in the Ajax Engine open source project. Now it's done. You can find a first version of it in the repository on Sourceforge: http://sourceforge.net/svn/?group_id=200182
and the sample web site http://www.mathertel.de/AJAXEngine was also published with this version today.
The current version will be tagged 1.5.nnnn.beta1 and a donwloadable zip file will also be available soon.
The OpenAjax hub specifications seems to be almost finished so not much work will be left until a final full compatible version.