I have only Java 6 JDK in eclipse.

Create server
Wildfly 8 (download and install runtime now works sanely- yay!)
gets error saying "No valid JRE's found for execution environment "JavaSE-1.8" even though I have "JavaSE-1.7" selected.

and when I change to 1.8 it says it can't find one for 1.7...something is weird.

Then I add Java 7, choose Java 7 and save.

When opening launch configuration it has Java SE 6 as the JRE system library for bootstrap entries.

So something is really wrong.