I don't see an "implicit fixed lifetime" here, but a committed lifetime to some point beyond our current horizon.
how is this unlike the current swamp, other than it being potentially a *lot* larger?
The current swamp is a block of allocations where the users have no formal agreement with any RIR. All IPv6 blocks are issued with a formal RIR agreement. The current swamp is a block in which a single organization often holds several routable prefixes, i.e. a small ISP asked for 2 class C's and received 2 non-aggregatable /24's. Most large users of IPv6 will receive only a single routable prefix and most PI IPv6 allocations, though smaller, will also be a single routable prefix. The current swamp is a block in which the allocations are not structured according to network topology. All IPv6 blocks are structured, at the highest level, according to continental-scale areas. At a more detailed level, PI blocks smaller than a /32, could be allocated according to some kind of topological addressing plan. For instance, RIPE could have a Scandinavia aggregate, CIS aggregate, Central aggregate (FR, DE, BE, CH, NL, PL, AT), Western aggregate (UK, IE, ES, PT) and Southeast aggregate (Ex-Yugoslavia, GR, TR, IL). There are plenty of grey areas when deciding which agreggate someone belongs in but the best way to handle it is not to draw lines on a map, but to ask the applicant where the bulk of their traffic will go and give them addresses from that aggregate. We are not doomed to repeat the swamp and we already have managed to avoid repeating some of the biggest problems that led to the creation of the swamp. --Michael Dillon P.S. the best way to deal with the bogeymen is to shed some light on the situation.