No, it just pulls focus off my HN window, changes Spaces desktops, pops off whatever was selected in iTunes before and replaces it with a link to a $49.99 iTunes app.
Hm. Yes, that could be irritating. I have iTunes set not to take focus, though, and I don't use Spaces (OT: Might I ask you how you set it up to work efficiently for you? I'm always curious about stuff like that), so I guess I hadn't thought much about how other people might experience the link.
I set up Spaces right when I got my Macbook, and it's hugely helpful. I assigned each of the major apps I use (Firefox, Terminal, Xcode, and Photoshop) to a different space.
Combine Spaces with SizeUp [ http://www.irradiatedsoftware.com/sizeup/ ] for optimal window management. Throw in Quicksilver and you don't even have to remember which Space holds which apps.
