No, not for 2005 
Some quotes from the announcement:
Visual Studio .NET 2003 shipped in July of 2003. This upcoming Service Pack will serve to roll up selected fixes that were issued after that release and before Whidbey. We have also included some triaged critical fixes and fixes included in VS .NET 2002 SP1. We anticipate that Customers will gain additional environment stability through the inclusion of these roll ups and the select set of critical fixes. We hope that VS 2002 customers may see this Service Pack as an additional stabilizing factor and proceed with plans migrating to the VS 2003.
...
Release Schedule: (these are estimated dates)
Beta Release 3/24/2006
RTM 6/1/2006
We encourage all interested parties to sign up to participate in the Beta. You will have the opportunity to use our pre-release product and notify us of any bugs you may discover. You may apply for the Beta by going to http://connect.microsoft.com
and signing up under "Available Programs".
...
Visual Studio .NET 2003 SP1 will provide the following fixes:
1. Hotfix and other critical update roll up
2. Released security patches/issues and other identified security fixes that satisfy triage criteria.
3. The top 50% Watson issues across the entire product.
4. Customer driven bugs
– Bugs will come from 2 sources, Watson data analyzed by the product teams and PSS.
Don't you love that sentence from the first paragraph? "We hope that VS 2002 customers may see this Service Pack as an additional stabilizing factor and proceed with plans migrating to the VS 2003." That's no typo. Enterprise clients are really slow to move to the new bits. Just last week in a customer meeting at an enterprise client of mine, I asked if a new Windows app was to be built with VS 2003 or 2005. Without a moment's hesitation my contact replied "there's no service pack for 2005 yet, we won't even consider using it." [I didn't dare tell him there wasn't a service pack for 2003 at that time luckily we are now covered if he asks about it.]
Kate