This is basically an updated version of Quicksilver, written by the guy who originally produced Quicksilver. It adds a few bells and whistles but until I have a packet sniffer hooked up to see what it is sending back to the Google collective there is no way I would touch this with a ten foot pole...
If I remember correctly, the main developer of QuickSilver (whose name I can't remember) was hired by Google some time ago. It wouldn't be surprising if he was involved with this.
I try to avoid the shareware download sites whenever possible; they're virtually useless these days and can be a breeding ground for adware. On the topic of the Google QSB, I'm going to give this a test run; I couldn't get used to Butler and I hosed my QS installation, so I've been looking for a good alternative.
Quicksilver is still better because it is more than a program launcher. QS provides a wide array of tools at your fingertips like a calculator, terminal commands, email commands, image manipulation etc.
Read the blog post all the way through: "Once you've found the result you want, we wanted you to be able to DO something with it. To find out what you can do, select a result and press the tab key or the right arrow on the keyboard."