The SQL Native Client (SNAC) provider was renamed from SQLNCLI to SQLNCLI10 in 2008. The means that connection strings that used the Yukon provider (SNAC9) won't work if you only have the Katmai provider (SNAC10) installed.
This will affect most SSIS users, as we use SNAC as the default connection manager for a lot of things. To resolve this issue, you have two options:
Starting in the February CTP (CTP6), SSIS can automatically update your connection strings for you.
Note, while SNAC10 is backwards compatible with SNAC9, there are some slight behavior differences.
New SSIS packages in Katmai will default to use SNAC10, but you can always switch the provider to SNAC9 if you have it installed on the machine.
What's New in SQL Server Native Client 10.0
Updating an Application to SQL Server 2008 Native Client from SQL Server 2005 Native Client
SSIS packages created in 2005 have to go through an upgrade process to run in 2008. 2008 packages created
We tried to make our package upgrade as seamless as possible, but one problem we've seen people running