I don't think there should be a conflict with Visual Studio 2008 because, if there was any conflict, it would have been with the 2005 and 2008 C++ runtimes but, if the runtimes themselves were a problem, even FSX ITSELF would conflict with Visual Studio 2008, because FSX is using 2005 C++ runtimes. We use instead the 2005 SP1 runtimes, because they are much safer.
On a properly configured Windows system, thanks with the WinSxS loading system, all different runtimes should work without any problems.