As of August 25th, 2009, Google Alerts now tracks links from emails through the google.com domain.
Previously, they didn’t.
Again, all in the vein that Google keeps grabbing more traffic so they can track your online activity (and mobile, as well), so they can better sell you more stuff.
I’ll continue to whisper my “The Sky is Falling” warning that the amount of traffic that is monitored by Google is way beyond comfortable for me, personally. When is too much, too much?