Yes, it’s important to distinguish between the two. At the partner conference in Denver Kim Saunders (Senior Director, SQL Server Marketing) said that they launch SQL Server 2008 in February, but the actual release will be in Q2. And by launching they mean that they have all the marketing material and the final product information, but not the product.

As for Visual Studio and Windows Server I have not yet heard anything similar, so I'm still thinking 27th for these.