James,
Updates of betas and milestone releases are not available over the update manager from either MyEclipse or Eclipse.
Secondly, I honestly wouldn’t encourage you to go through all the trouble upgrading to M7, as there is a JSP validation bug in our beta (doesn’t show errors) and as far as I can tell, nothing truely fantastic happened in that release. I would suggest either hold out for 3.1 stable or stay where you are if everything is work.
If you DO need to upgrade for whatever reason, you can export your preferences using teh Export button on the bottom of the preferences Window, also keep in mind that your formatter settings and code templates are exported individually, you must navigate to those preferences and use their export mechanism.
As far as MyEclipse is concerened, all of it’s preferences will be correctly exported for you, and the rest of the MyEclipse information is stored in your project in the “dot” files, so you should be fine.