I would bring your welcome message to the top of the page...
between the header & the nav bar and personalize it a bit to make
your visitors fell more at home on your site...
(since thats 1 of the first trhings they'll see)
you can compensate the empty space at the bottom by aligning your top sites vertically / horizontal, which ever fits / looks best...
Other than that it looks fine...
Good Luck on your site...
