  The discovery of the 6.67 hr periodicity in the X-ray source 1E 161348-5055
associated with the supernova remnant RCW 103 has raised interesting
suggestions about the nature of the X-ray source. Here we argue that in either
accreting neutron star or magnetar model, a supernova fallback disk may be a
critical ingredient in theoretical interpretations of 1E 161348-5055. We
further emphasize the effect of fallback disks on the evolution of young
compact objects in various ways, and suggest that even SS 433 could also be
powered by fallback disk accretion process.
