8.1 beta1 -> beta2 upgrade question

Hello,
I am a systems admin for OmniTI Inc.  I'm posting this question at the
request of my boss, Theo Schlossnagle.  I am new to Postgres, but Theo
has asked me to engage some developers for help, so please bear with me
and forgive my ignorance.  

We are testing a 1TB database on 8.1 beta 1.  The upgrade path to beta 2
(and presumably from beta 2 to the next release, all the way through
production) requires a full export and import.  Even on our beefy
hardware (quad-Opteron, 16GB RAM) we are looking at a 26-hour complete
outage for every upgrade (and back-out if something doesn't work
properly).  We are interested in finding a way to directly translate the
data files from one version to the next.  We can devote resources to
work on this if the development team can give us guidance.

Thanks in advance,
Eric Sproul