One of the problems about being religious about technology is that you believe your own hype and start drinking your own kool-aid. That's what the SIP loyalists have to start thinking about. Being protocol specific versus being protocol agnostic can be the death of anything. Remember the joke that Microsoft is only one OS away from being out of business. Well companies that rely solely on one IP protocol are always in danger of being put out of business by the next hot flavor of the month.
H.323 was all the rage until SIP came along. Now, SKYPE with a "free" model that is gaining users faster than SIP carriers are, has turned the world on its side. Rather than fight, or dismiss the upstart technology, I think its better if SIP experts figure out how to integrate SKYPE and SIP together.
Why fight success. Go with the flow......and work in harmony....
Hat tip to Rolando for his pointing out the Cook Report which Stuart gets the credit for first finding and mentioning. Read the Cook Report. Lots of good stuff there too.