Well, I mean I know they are Google and all- but I can't imagine Gmail and Gcal supporting a corporate user very effectively. I use it for my personal stuff, but I am extremely appreciative of Exchange at work.
Edit: maybe that? http://code.google.com/p/radishdisplay/
* Update: Specifically for you, rather than in the wider sense; how does Exchange make /your/ life easier?
Offline is a smoother experience requiring no effort. Reminders for the Calendar actually manage to get my attention.
Rules are easier to manage, and if memory serves much more flexible.
I am not criticizing Gmail et al mind you; as I mentioned, I use them all the time. They just are more useful for personal, low-volume stuff.