Unfortunately it has shattered. In Israel the original Kakh organization split into two groups while in the USA the original JDL became secularized and de-Kahanized to the point where they're now just a slightly more militant version of the Anti-Defamation League.
Kahana's associate Chaim Ben Pesach (whose site I can't link to from FR because it's so "extreme") is still around (he's forbidden to enter Israel) and has his own web site and organization as well as affiliates in Israel.
You can do a web search or I will send some links via PM if you're interested.
Thanks. I would be interested in the links - just to keep up with the range of things going on.