net-www/netscape-flash-10.0.20.7_alpha is native 64-bit but is masked by profiles/default/linux/amd64/2008.0/no-multilib. Expected: no-multilib profile should not mask native 64-bit Flash, which requires no 32-bit libraries.
angelos did this the other day, he is the main amd64 dev dealing with no-multilib stuff; you may want to ping him in irc in the future for these requests. Thanks.