When are we going to ask the right questions on this topic?
Google have deflected with the age-old "caveat emptor" but that's simply not good enough any more.
When the public as a whole (not just us paranoid geeks) do not yet have the tech-enlightenment required to understand how some of these mechanisms work, just sticking up a dialog (Vista UAC, android application access permissions dialog, etc etc etc) WILL NOT DO.
This clunky mechanism works for the geeks who created the environment in the first place: unless we ask the question "how do we get Joe Schmoe to understand what this app is asking for?" we will continue to see stuff like this on every platform which can download executable content.
In the meantime, I'll keep wearing the tinfoil hat and say "no" to everything where possible until the tech industry wakes up and interfaces with the average "idiot" properly.