Hi,
Unfortunately this plugin does not come with the same LGPL license as FCKeditor, instead, according to the JW_FLV_MEDIA_PLAYER_README.HTML included in the download, it is licensed under the Creative Commons License and is only free for non-commercial use and requires 20 euros for a commercial license. As such it is truly open source in the sense of the OSI definition and is not compatible with mojoportal and we cannot include it or distribute it with mojoportal.
However, there is no problem with people using it if they want to integrate it themselves. If you would be interested in writing a tutorial with screen shots and step by step instructions I could create a page and set you up with edit permissions.
Best,
Joe