Amazon and others already have release images with PostgreSQL installed, however as part of getting some datamining software built on EC2 I have run thru the build of Bizgres.

Most of the time was spent getting java installed properly. I will release a recipe soon as mentioned in that post.

On the Openfiler front I have read some more documentation, wiki and forum posts and will give it another crack on the weekend.
I know there are bunch of people interested in seeing Oracle RAC on EC2 a reality.

There are several other options to getting shared disk available for OCFS2 to see and use. I will only explore those if the problems with Openfiler are intractable.

Update:
The Bizgres build was good I have run through the IVP (Instance Verification Program) without issue, see the details here.

Have Fun
Paul