You need to make it a lot clearer (or easier to find) that you can’t use Pulse to upgrade to ME 2013.
I went to the Customizing and Updating MyEclipse document
http://www.myeclipseide.com/documentation/quickstarts/install_update_sites/
…and it doesn’t say anything about this.
I also tried the FAQs, and found:
FAQ: [Installation] How to upgrade to latest release:
https://www.genuitec.com/forums/topic/installation-how-to-upgrade-to-latest-release/
which doesn’t mention this issue either.
After I found this forum thread, I went back and checked the FAQs again, and did find this one:
[MyEclipse 2013] Pulse & MyEclipse Configuration Center
but this should be renamed, since the title could easily be interpreted as relevant for people running ME 2013 already, whereas it really applies to anyone trying to UPGRADE to ME 2013. Maybe title it “Upgrading to ME 2013”?
You might also want to update the ME Roadmap page (http://www.myeclipseide.com/module-htmlpages-display-pid-329.html) since it says 10.7 is “Projected Q4, 2012”, and ME 2013 is also “Projected…”.