For all those folks who were living in the 9.2 world with the extended fee waived . It seems that July 31st is the date when oracle takes away that support and customers will have to pay for extended support which will go thru 2010 . Metalink Note 392222.1 has details about this .
As far as 10.2 upgrades go Oracle has been working on documents like the Oracle 10.2 Upgrade companion and SQLTXPLAIN for working with upgrades. The Upgrade COmpanion can be found as Note : 466181.1 and has alot of good info about the upgrade process as well as safeguards for the database. I'm still workign on trying out the stored outlines suggestion to see if that helps in a situation where oracle would change an explain for the worse