Historically, its been a major hassle for our team to import our multi-module Maven project into Eclipse given all the Flex, WTP, and GWT stuff in there. We were recently think
maven eclipse plugin and m2eclipse (now m2e) are independent projects. They stopped working together from 2.7
release of maven eclipse plugin (when maven eclipse plugin dropped eclipse:m2eclipse
goal).
I believe you can use maven eclipse plugin with Eclipse if you do not have m2e plugin, but the support, especially for wtp is limited, if not non-existent.