@Pierce: I sense a pun in about blog posts in there somewhere.
Rearranging blogs is fun, not at all like sewing rooms as far as I can see.I like the direction it's going. Three columns is a useful format. Colourwise it's looking good and Hill Cantons is a good model. You could narrow the sidebars just a little to get more room in the middle maybe. It's a tricky balance. If you're finding the sidebar images are too wide, just jump into the individual widgets and resize, either proportionally by dragging the frame, or in the code by changing the numbers. It's worth recording the starting numbers to help keep the proportions as you tinker.
I didn't mention you might also be able to widen the whole three columns, i.e. narrow the marble effect edging. That function is under Design > Template Designer > Adjust widths. I can set 'entire blog' to 1000 px so it ought to be possible for you too if you want to go that way.