The answer of course, is yes. You'll need to log into the Definition Center with Administrative rights to make changes. Once you log in, select yourself in the top right, and then 'Administration & Settings'.
Among all the fancy Administrator options you have, select the 'Customizations' option.
Scroll down to the 'Home Screen' section, and add your logo. Don't forget to hit the save button down at the bottom.
Now you're all set! Fun fact: If you don't see your new logo, it's probably because the site is cached.