I am amazed how fast is DB2 version 9.7 moving into production. It is much faster then 9.5. I started to see first signs of 9.5 used in production for about 1 year after release.
DB2 9.7 is entirely different. Its already used, deployed on testing systems and used as standard version for new projects. Its pretty good success because there is not even single fixpak for v9.7 out. Fixpak 1 is awaited because it will add Oracle compatibility to DB2 Express Edition, which is very good news for application development.
There are sure some minor issues with 9.7 but benefits from 9.7 are so big that migration from v9.5 is pretty common. On other side i dont see too much migrations from 9.1. db2 9.1, db2 9.7, db2 9.5. My observations also confirms Google trends graph:
Version 9.1 continues on just slightly degrading rate, but v9.5 is being replaced by v9.7 fast. Also only version 9.7 captured enough media attention to have news volume graph displayed.
This trend is vastly different from Oracle 10gR2. Because existing 10gR2 customers have currently no interest to migrate their applications to 11g. Independent Oracle consultants share this opinion too. Oracle migrations are quite difficult process and there are not worth doing if old version is still supported and there are no clear benefits from migration. Don't fix it unless its broken. Also in Oracle camp Gold Standard is to wait for Release 2 so important bugs gets fixed before even planning migration.
DB2 9.7 is often considered Best DB2 Release in 25 year history. I agree with that, feature list is really very impressive. In fact it fulfils all my secret (and sometimes asked) db2 feature wishes. Lets make a quick list:
DB2 9.7 is also much easier to work with and performance improved a bit over 9.5. As you can see yourself there are huge benefits from migration!