I currently have Visual Studio 2008 Professional installed on my Windows 7 (x64) laptop. I also have SQL Server 2008 Express and Crystal Reports 2008 installed.
Can I upgrade Visual Studio 2008 Pro to Visual Studio 2010 Premium and if so do I have to make any configuration changes to any other apps I have installed?
no, you cannot "upgrade" Visual Studio in the traditional sense. Visual Studio exists side-by-side (sxs) with older versions, so you have both versions installed. What does get upgraded is the CSPROJ (or VBPROJ) files that represent your projects.
It's a side-by-side install, you can continue to use both installations for development. As for other two:
Your SQL Server will continue to work for both VS2008 and VS2010, SP1 adds the .Net 4 support.
Crystal Reports will not...however there is a new 2010 version, just not included in the base Visual Studio install anymore. It will be available as a separate (still free) download from SAP. It's currently in beta 2 status (as of the time of this answer) but should be released sometime soon. SAP updates the current status at this blog here so you can keep track: http://www.sdn.sap.com/irj/scn/weblogs?blog=/pub/wlg/14514
