New developments for IPv6

New developments are possible only if you deploy IPv6 and use it
"Killer app" discussion seems moot

Application designs on network without limitation of NAT
Peer-to-peer fits well
Web camera/chat/VoIP with less scalability limitations (serverless/NAT-less)
Directory of service/service discovery?

Security model?
Firewall model isn't sufficient - see how many viruses you see every day
Beyond the firewall model - "Fire suit"?
Security model for public access network (like hotspot wireless)

Fixing various IPv4-only APIs
DBMS, proprietary APIs, libraries
Educational materials