Why haven t the other clients adopted limewire technology?

I was wondering why the other client developers haven't adopted ultapeer technology or swarmed downloads? A little competition is by all means healthy to spark innovation but embracing new technology is also good too and it will help gnutella as a whole.

I'm guessing they want LimeWire to work out all the problems and etc. If every client implemented what they thought an "ultrapeer" should be, gnutella would definitely turn to crap.