This will be a quick pass at creating a configurator so that we can get feedback from users to make sure that we're going in the right direction.

I think this issue depends on http://jira.codehaus.org/browse/MNGECLIPSE-380 since flex-mojos use extension tag.

I don't see any issues with extension tag in examples from flex-mojos. As I already mention on the mailing list, please attach test projects to MNGECLIPSE-380 that would allow us to reproduce issue.

In flex-mojos samples we are using inherit from flex-super-pom.
And on flex-super-pom is declared the extension.

VELO

In flex projects all dependencies are with custom types (normally <type>swc</type>)

VELO

We can't integrate Flex Mojo if m2eclipse does not support extension plugins

I'm curious what people are doing as a workaround. Copy the flex files (1 SWF in our case) by hand or via an ANT script?

The current workarounds are documented here:
http://code.google.com/p/flex-mojos/wiki/FlexBuilderIntegration

You can see on http://code.google.com/p/igenko/wiki/SetupProject the workaround that we use on our project.