I've ready a thread in russian Nginx maillist about implementing HTTP/SPDY over SCTP in future.
I realize that SCTP is completely unusable for public service at the moment, but what changes should happen for SCTP to replace TCP for public web?
Why SCTP, I wonder? SPDY specifically implements the multiplexing itself within TCP because SCTP isn't practical in the short term.
In my understanding, the biggest barrier to SCTP deployment today is support for the protocol in the operating systems of endpoints, and support for the protocol in transit in NAT and firewall network devices (anything that needs to actually be able to inspect the protocol).
Most decent firewalls will let you allow an IP protocol number, but support for more granular port rules and connection tracking for NAT is a must for widespread deployment. NAT support in consumer routers is going to be a real barrier - those devices don't tend to be very close to the "cutting edge" of decade-old internet standards (say, for instance, IPv6).