They probably aren't but then the PR tool is provided to everyone, not just webmasters and SEOs. How many people use things like Froogle, University Search, Print Search, Translate, etc. Probably not many but when G knows that any of their services are not working a status bar could be used to let their users know about this. This is just common courtesy.
Of course you do. Many PR4 sites are more relevant than PR7 sites for specific searches. That has always been the case.