Looks awesome, but i miss the modules like projects and bookmarks
No, just kidding, i know, that this is a sneak preview.
Just some hints for you:
The adressbook could get more powerfull, if you make a contact histoy.
(-> companies need a crm, and also myself would switch from my customized GO to the new PRO-version!!!)
The projects module would become a killer feature if it looks like the solution of eGroupware.
The drag'n'drop from the calendar is nice, but you can't move it from one calendar to another.
Is such a solution even possible with AJAX?
But, at last, even if i dislike AJAX, i think it is neccessary to go this way.