Filing at aroben's request.
Running Safari.exe from %TEMP%\WebKitNightly gave an error about CoreFoundation.dll missing and running run-webkit-tests crashed on each test. Adding "%TEMP%\WebKitNightly;C:\Program Files\Safari;" got run-safari to start.
I tried copying the DLLs as suggested at http://trac.webkit.org/wiki/BuildingOnWindows#Runningthetests, excluding WebKit.dll and now both run-safari and DumpRenderTree.exe crash on startup (more specifically, pull up the VS debugger). Running Safari.exe from %TEMP%\WebKitNightly from gives the CoreFoundation.dll error again.
I was able to reproduce these problems, and I think I have a patch that fixes them.
Created attachment 29653 [details]
Created attachment 29654 [details]
Fix running run-safari and run-webkit-tests from outside the source tree
Created attachment 29655 [details]
Created attachment 29656 [details]
Created attachment 29657 [details]
[3/3] Fix running run-safari and run-webkit-tests from outside the source tree
Landed as r42717, r42718, and r42719