One of the things I love about my very small sewing room is the central cutting table. I can walk all around it. I like having access to all four sides of the table. Right now it's just a table, but when I re-do the room we plan on making a table with built in shelfs/drawers under it to store "stuff".
Also if you can ... try to plan for a design wall that can accomodate the largest quilt you can make. Mine is small (WOF by 6' tall) and I'm always wanting more. When I re-do my room I'm hoping to plan it so that one whole wall is a design wall.