Ececutive summary : put the vm argument on the line after "-vm" in eclipse.ini.
I got the following dialog after a fresh Eclipse install :
The Maven Integration requires that Eclipse be running in a JDK, because a number of Maven core plugins are using jars from the JDK.
Please make sure the -vm option in eclipse.ini is pointing to a JDK and verify that Installed JREs are also using JDK installs.
The Installed JREs were already pointing to a JDK. I set my my eclipse.ini to : -vm C:\Sun\SDK\jdk
Eclipsepedia has an eclipse.ini.
I put the vm location on the next line and everything worked.