When you try to install a project from Central it shows a missing requirement:
m2eclipse-wtp >= 0.13.1
Not sure why this happens since the plugin is in Eclipse in version 0.16.0:
org.eclipse.m2e.wtp_0.16.0.20120830-0951.jar
If you click Install, you will get a NPE:
Problems occurred while performing installation: null
java.lang.IllegalArgumentException
This is in the workspace log:

!ENTRY org.eclipse.mylyn.discovery.ui 4 0 2012-09-04 11:36:50.475
!MESSAGE Problems occurred while performing installation: null
!STACK 0
java.lang.IllegalArgumentException
	at org.eclipse.mylyn.internal.discovery.ui.PrepareInstallProfileJob_e_3_6.run(PrepareInstallProfileJob_e_3_6.java:88)
	at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)