[osth]

I wonder if header compression is primarily to allow for ubiquitous, large cookies.

Cookies were originally and with few exceptions remain a hack to try to add state to transactions that were not intended to be stateful.

If indeed the header compression is driven by the growing prevalence and size of cookies, then HTTP/2 is an effort to accomodate a hack. Not very interesting.

Some hacks that find their way into RFC's are difficult to remove because the transition process would be unreasonably expensive, like replacing the "sophomoric" compression scheme in DNS with something more sensible like LZ77 (credit: djb). I guess we might see some passionate arguments by web developers about the great expense of removing cookies from the HTTP standard and replacing it with a session facility, but I think the (long term) benefits easily outweigh the (short term) costs.