Could you consider adding a decent 3-column theme. Your current choice is very limited!
I found a really cool one (link below):
It has a photo header (a must!) and 2 widget-ready sidebars that are located on both side of the main body (I find this structure nicer than having them on the same side)
WordPress.com is doing a great job and I really enjoyed it so far. I am just impatiently waiting for new developments.