Egress Filters - Can They Solve The DDoS Problem?

dhammabum asks: "Considering that egress filtering is the fundamental way to prevent distributed denial of service attacks (DDoS), could ARIN, APNIC, RIPE, and national NICs band together and force registered IP address holders to apply egress filters against their networks? It seems to me this is the only way to truly stop this problem (and reduce other crack methods), and NICs have the authority to actually enforce it -- no filter, no routing of your packets. I can't, though, think of an easy way to test it. What do you think, is this a practical measure? Or do packets, along with information, 'want to be free'?"