I like your board, but would like one with ethernet. The chip you've selected already contains an ethernet MAC, so all you need to add it a PHY, but I realize, you're low on space.
Nice board, but it looks like if the traces to the SD-RAM are all of different length. I've not tried to do such a layout my salve, but have read about more than one project, where they had to do multiple layouts, because the unbalanced lines to RAM causes phantom bugs.