Re-enable VS debugging for the beta
The debugger in LINQPad 4.5 is awesome, but not as good as Visual Studio's. Before the beta, I was using Debugger.Launch/Break to debug in VS. Now, those launch LINQPad's debugger. Unless and until the debugger is as good as VS's, I would like some kind of button or something (as long as it's faster than using the preferences) to use an external debugger.
This is easy to work around - run your query with Ctrl+F5 (run without debugger) instead of F5.
Alternatively, uncheck the 'Break when exception is unhandled/thrown' buttons on the toolbar, and delete any breakpoints. LINQPad then runs your scripts without a debugger by default, and Debugger.Launch() will work as before.
Ethan Reesor commented
Just now I relaunched LINQPad (beta), and Debugger.Launch/Break launched VS. So maybe it works if you haven't used the internal debugger yet?