I started doing the exact same thing last weekend (porting that package to GXT.) I got about half way through and realized that it was a fairly sizable project and thought I'd look around a little longer before attempting to complete the job. Sounds like I could help you out and maybe we could have it working in fairly short order. Here's the bits that I didn't really thing were that great:
1) The event model is wrong/different. That's going to make it a challeng.
2) I'd like to have something that I don't have to maintain long term. These editors are out there by the shed loads and surely one of these guys can do a GWT/GXT port and then I'd not have to maintenance it.
3) My 'needs' are a bit less that what this provides in some areas, however I'd need to extend what it does in others. In particular, uploading images and videos to my server and then selecting them from the server (with funny sort of link names) to embed into the document would be a must for me.
At any rate, I'm willing to help out. How should we proceed?
First i would like to appologise for my late answer i had a busy week. Thanks for your interest in the editor.
Before we can work together on the editor i have to refactor the editor in a separate module. After that i will create a project at google code or sourceforge and create a demo. I presume the demo will attract more people to help us.
As soon as i have finished the project creation and checked in the source i will leave a message here. I think i will need about a week.
@maku: I have something usable. The screenshot shows the RTE fully integrated in a gxt environment and we use the editor already in a productiv system. As mentioned before, the editor is in a basic state but stable as far as i can say.
at the moment it does not have more features than the gwt provieded rich text area. But you have to implement a toolbar to operate the editor youself and the options of the gwt rta are limited. Thats why i took the html gwt-html-editor.
@kht: I think integrating tine_mce via JSNI is a good approach to get a full featured rte with less efford. But if you want to integrate the editor into your look and feel and if you want to configure the editor more deeply or adept the code to your needs it would be nice to have an gwt/gxt based editor. Don't you think so?