The Greater London Authority is also ditching Oracle in favour of PG. I consulted them while they kick started their transition and the first new PG/PostGIS only project is already delivered. The number of companies ditching Oracle is probably much larger than it seems, giving the dynamics in salaries. The average PG based salary goes up steady, while working with Oracle is going down pretty quick.
At least, so it would look from the UK. An Oracle DBA in average is currently offered some 15% less than a PG dba.
My 10p
Bèrto