The WAL log/hot standby you can read from in 9.0 are big. Back when I used PostgreSQL they were the biggest missing features that I wanted.<p>If you're doing reporting then you really care about analytic queries. That is in 8.4. But the truth is that most developers don't use their databases in ways where they will benefit. However if you run across cases where you think, "I wish I could just suck this data out, sort it this way, then do this simple processing/grouping and upload that back into the database" then you have probably run across a use case for analytic queries. With analytic queries the only cases where I've had to do that are to join data that is not in the database, to process datasets that were too big for the database server to physically handle, and once because performance really, <i>really</i> required it.
I wish they had a click, click, click and boom -- easy data replication to another server. Same with just hot backups where I could setup a backup job that runs on the hour and lets me fallback to any hour in at least the last 3 days if I have an issue.