Scott, your work on HOWL has not been in vain. Many Linux/Free Software people (including me) learned to know Zeroconf with your software. Without the troubles surrounding the licensing, I would never have started what is now known as Avahi, and HOWL would still be the number one of the Linux mDNS/DNS-SD implementations.
The HOWL legacy will live on, since Avahi includes a HOWL compatibility layer which will be kept around for a while.
A year and a few weeks ago Trent and I decided to merge our efforts and form Avahi from our seperate works. I wonder how much time it will take us until we see a similar R.I.P. note from the Bonjour camp, on our route to AVAHI WORLD DOMINATION. ;-)
In contrast to what Scott wrote in his announcement, Avahi is far from being strictly Linux. Avahi has been ported to FreeBSD, OpenBSD, MacOSX and recently (not yet official) Solaris. (However, he's right with what he writes about me.)