Good Read - David Chappell: SharePoint 2010 - An Introduction for ASP.NET Solution Architects
What is an application platform? It’s a broad concept that can include a range of interconnected technologies. ASP.NET is a platform for creating Web applications, for example, while at the same time it belongs to the larger application platform provided by the .NET Framework. Because the SharePoint 2010 application platform is based on ASP.NET, learning how to use it isn’t a huge learning curve for ASP.NET developers. But when does it make sense to build an application on SharePoint instead of on raw ASP.NET? The goal of this paper is to answer these questions. Doing this requires describing what the SharePoint 2010 platform provides and looking at the types of applications SharePoint is designed to support. If your application can benefit from the SharePoint framework, building it on SharePoint will enable you to focus more on creating value and less on building infrastructure.
External source: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=5184cb27-98d9-4cc0-bb0b-4b24d5b62db6
