Creepiest Part of Jesus' Death and Resurrection in the Gospels

There is a small detail that Matthew adds to Mark's narrative concerning the broader effect of Jesus' death and resurrection:

the tombs also were opened, and many bodies of the saints who had fallen asleep were raised, and coming out of the tombs after his resurrection they went into the holy city and appeared to many.  (Matt 27:52-53).

The line to inspire every zombie apocalypse to come:  the dead climbing out of their graves to mingle among the living.  Or so it seems.  From an ancient Jewish perspective, it appears that Matthew is saying that Jesus' resurrection has triggered the general resurrection (Paul says something similar--that Jesus is the "first fruits" of the resurrection, suggesting the season of resurrection is at hand for the rest of the "fruits").  The general resurrection occurs at the end of time (or the end of the age), which suggests that at Jesus' death and resurrection the "Kingdom of Heaven" has broken into this world.  But, still, the imagery to express this resurrection-theology is rather gruesome.  Happy Easter!

UPDATE (April 1, 2013):  Jim Davila raises some additional questions of this passage here, and refers to another discussion of the passage found here.