problem of the Internet 

compromise of the e2e principle
"do not replicate in lower layers what can be handled by higher layers"
has taken a beating this decade (and it's still early)
in its place, a web of contracts to control what people are allowed to do
saddest part: we had a different solution (IPv6), but too little too late
NATs, firewalls demanded viscerally by the market
the same brilliant community ultimately brought you both in (some defn of) parallel
we have the Internet [un]layering we deserve
it's a mess to be sure, e.g, IPSEC through NATs/firewalls
"sometimes the price of freedom is what freedom brings"  -- eric schlosser'sreefer madness
we have failed you (sysadmins) by engineering our way toward the unsupportable 
maybe if more sys and net admins had been in some of those IETF WG meetings....

need to be realistic about where to go from here
IPv6 will be hard-pressed to revive e2e legitimacy (tho it has believers)
don't think we're getting the e2e architectural assumption back
need to think outside that box from now on
right solution at time t might not actually be the right solution at t+1
not too late for admins to get [back] in on the fun