Gmail is safe, as long as you avoid falling for phishing scams
googleonlinesecurity.blogspot.com
googleonlinesecurity.blogspot.com
All web mail (or any other system) is just a step away from the next exploit. The difference in my mind between web mail and regular mail is there another dangerous attack vector (XSS) which is only fixable by a single vendor.
The standard mail servers companies use are often vetted patched from many sources and can be hidden behind some pretty well tested encryption protocols.
Trusting mission critical things like domain name registrations to web mail seems like an unacceptably big risk to me. While XSS wasn't the issue this time, it clearly has been in the past.
What?
What about bugs that aren't disclosed?
The community would curtail such a site after awhile, but those prior may have been hacked.