In my previous post I explained that MSDE would not be supported on Windows Vista. I have answered a number of questions inline - but I wanted to move the dicussion on from "why?!" to "how do we do that?".
When I owned the UK efforts on early adoption of SQL Server 2005 for ISVs we overall had a very good experience moving applications over from SQL Server 2000 to SQL Server 2005. The large majority worked with no or very minor (albeit often repeated many times) issues. ISVs were very happy with the compatibility level we delivered. Since that work, SQL Server 2005 has shipped and the information on upgrading applications to SQL Server 2005 has expanded significantly.
You will find this information grouped under http://www.microsoft.com/sql/solutions/upgrade/default.mspx.
But I wanted to pull out some specifics:
Hopefully the above will prove useful.
P.S. I would love to hear experiences (good and bad) from folks who undertake this move.