In August 2007 the IETF HTTPbis work group started to make an update to the HTTP 1.1 specification RFC 2616 (from June 1999) which already was an update to RFC 2068 from 1996. I wasn't part of the effort back then so I didn't get to hear the back chatter or what exactly the expectations were on delivery time and time schedule, but I'm pretty sure nobody thought it would take almost seven long years for the update to reach publication status.
On June 6 2014 when RFC 7230 - RFC 7235 were released, the single 176 page document has turned into 6 documents with a total size that is now much larger, and there's also a whole slew of additional related documents released at the same time.
2616 is deeply carved into my brain so it'll take some time until I unlearn that, plus the fact that now we need to separate our pointers to one of those separate document instead of just one generic number for the whole thing. Source codes and documents all over now need to be carefully updated to instead refer to the new documents.
And the HTTP/2 work continues to progress at high speed. More about that in a separate blog post soon.
More details on the road from RFC2616 until today can be found in Mark Nottingham's RFC 2616 is dead.