<p>I will be moving our production SQL2005 application to SQL2008 soon. Any things to lookout for before/after the move? Any warnings, advices?</p>

<p>Thank you!</p>

The upgrade adviser can also help.
Look at the execution plans with production data in the database.
Though my best advice is to test, test, test.
When people started moving from 2000 to 2005 it wasn't the breaking features that were show stoppers it was the change in how queries performed with the new optimizer.
Queries that were heavily optimized for 2000 now performed poorly or even worse erratically leading people to chase down non-problems and generally lowering the confidence of the end users.