If you only want to move your Quicksilver settings, copy everything in
~/Library/Application Support/Quicksilver to the same location your
new computer (~ stands for your user's home folder).
However, I suggest that you use the Migration Assistant to move all
your data, preferences, applications, etc. to the new computer.
Migration Assistant runs as part of the setup process when you get a
new Mac from Apple, and can be run again at any time by finding it in /
Applications/Utilities.