Whoops, looks like my fault. We're moving from m2e 0.12 to 1.0 in the next JBoss Tools 3.2.1 release for Helios (Eclipse 3.6.2), and I suppose I moved the requirements site  up too soon.
To resolve those dependencies, you can either add this URL to Eclipse to get the bits we used for building JBoss Tools 3.2.0 (m2e 0.12.1 and m2e-wtp 0.11.1):
Or, use these sites to install the latest 0.12.x content:
If you want to try our almost-but-not-quite 3.2.1 release, it's available here:
Let me know if that solves the problem for you.