hmm I should seriously start using thunderbird for gmail, so that all my eggs are not in the same basket.
The point is not about using a client/webmail it is about using GMail.
IMO, Google would not do anything to screw up the reputation that they've oh-so-carefully built in the past decade. It will be ridiculous if it was expected of each and every person to host a server. I agree that privacy is not guaranteed when you use such services but these are risks that are inevitable.
Regards, -Aswin.