There we go, someone else noticed it too. And him, being a much more established blogger, got more responses that actually had information. There's also an amazing number of trolls. o.O WTF, people, read what the blog actually says before trolling. You look frightfully stupid.
In short, someone did a tcpdump on the traffic, and discovered that:
a) It requests the two URLs: http://www.apple.com/widgets/widgetadvisoryhttp://www.apple.com/widgets/parser.info
b) Responses include a signature and some SQL code.
So, it's relatively harmless. Unnecessary, IMO, but, eh, I wonder if it was in the upgrade agreements somewhere? The calling-home, I mean.
Apparently, by way of digg [http://digg.com/apple/Disable_OS_X_Dashboard_Advisor]
, a way to disable is:
sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.dashboard.advisory.fetch.plist
Disabling probably isn't really necessary unless you pay by the number of bytes you transfer. Or have a system so slow that just the very act of the daemon running will cause a systemwide delay of several minutes.
I'm disabling it, 'cause I don't use dashboard at all. So there's really no point in it running in the first place. Dashboard's not quick enough; I'd rather a command-line based thing, as I don't like having to move between mouse and keyboard, and most of the time, I'm on my keyboard.