The static features in Groovy 2.0 look like they were integrated from the Groovy++ project. Seeing as how there was an entire side-project created by the community I'd say there was a big interest in adding static type checking to Groovy.
The static features were not integrated from the Groovy++ project, as it differed in various ways compared to what we had in mind for Groovy. But Groovy++'s definitely been a great inspiration for us when we developed those features, and the project clearly showed the interest of the community for that.
http://code.google.com/p/groovypptest/wiki/Welcome