That RFC is marked as "PROPOSED STANDARD" which is why I saw it as work in progress but you're right, that seems to be the end of the road for RFC's (for example RFC 6455 December 2011 (websockets) is also marked as proposed standard but this is what everyone has implemented)
The IETF deliberately has no power whatsoever. Whether an IETF standards track proposal in fact becomes a standard everybody implements is entirely up to the implementers. This is in contrast to many standards development organisations (and indeed whether the IETF is even an organisation is open to doubt) which are government functions and can produce de jure standards you're obliged to implement or in the worst case force may be exercised against you by those with a monopoly on its use.
As a result IETF standards are only proposed and that is as you say "the end of the road".
> As a result IETF standards are only proposed and that is as you say "the end of the road".
Not really, after PROPOSED STANDARD there's INTERNET STANDARD, the STD series. For instance, IPv4/ICMPv4 (RFC 791/792) is STD 5, UDP (RFC 768) is STD 6, TCP (RFC 793) is STD 7, DNS is STD 13, and so on (STD 1 has the full list).
However, an IETF standard only reaches that level after it's been in use for a while; according to RFC 2026 (BCP 9), "A specification for which significant implementation and successful operational experience has been obtained may be elevated to the Internet Standard level. An Internet Standard (which may simply be referred to as a Standard) is characterized by a high degree of technical maturity and by a generally held belief that the specified protocol or service provides significant benefit to the Internet community."
