This is a very wise decision because the javafxrt.jar is on the extension classpath and has been holding classes who depend on swt which is a client library typically found on the application classpath or in OSGi in the Classloader of the SWT-OSGi-Bundle.
I guess you can imagine how hard is was for e(fx)clipse to give OSGi-User the FXCanvas integration. This problem is gone now. The latest nightly build can deal with the changes on the JDK-Level (for FX2 the classloading magic is still in).
In case you are developing with JavaFX and need the SWT-Integration you’ll have to update to the latest bits in case you use JDK8b113 and above.