This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Well, I'm not an expert, but just like all other strong standards there's no need for the change, like HTTP 1.1 didn't changed since 1999 and others.
There are already too many usages of it like this, and people are happy with it or got used to it.
WSDL 2.0 IMHO doesn't bring too much improved stuff.
People are also afraid of change.
It's like changing cars which work on gas/diesel like forever, in electric / hybrid cars. Nobody buys them.