The process of state change via "Pasting" is specific to individual applications, as such there is no magic way to discover whether the state of an application changed after accessing the clipboard.
The best you can do is detect whether an application has retrieved data from the clipboard. Again, there's no way of knowing what the application did with this data. It's akin to knowing someone opened their frontdoor without knowing where they went, if anywhere.
If you do want to try this you could do something like hooking the GetClipboardData function. For information about how to palce system-wide API hooks check out the samples in Micrsoft Detours - http://research.microsoft.com/sn/detours
