Spring roo is new framework and I found it very interesting. I have been working on web application for last 3-4 years and Always found JSPs are hard to maintain across teams if
First, Spring Roo is a code generator tool (similar to Grails commands system):
(source: springsource.com)
Second, Spring Roo applications currently use Spring Web Flow for the view and Spring for the glue.
So, while you can compare (Spring Web Flow + Spring) and (Wicket + Spring), the later combo doesn't offer anything comparable to Roo out of the box (maybe AppFuse or AppFuse Light but you didn't mention them and they are third-party projects).
In other words, I don't think that "Spring Roo vs (Wicket and Spring)" makes sense.