It'll be a long time before WWE guys aren't all over the ECW show, if that ever happens. I, for one, believes it will happen, but yeah, not for a good while.
It wouldn't shock me for any of the following to happen to keep things going:
-Someone from ECW turns on the group to join WWE
-Someone from WWE wins the ECW title
-Someone in ECW, RVD perhaps or maybe even Sabu, gets the WWE title once again (after RVD loses it)
-I can see an ECW guy with the WWE title and someone in WWE with the ECW title, and their having a match together just to make things very screwy