DIV's are the way to go. I used to use tables before knowing any better and since I started using DIV I've never gone back. Table are not made for layouts, rather data display. DIV is cleaner, easier to read and the just "work".

Clean and messy code doesn't make any difference as to how easy a design is to steal. Its just a matter of a using a visual editor. A person who writes messy code is not a good coder. I'm a DIV-lover however I have never made a wordpress layout and will never intend to. DIV and Wordpress have nothing to do with each other just so you know. DIV's are found in most websites today and only more older websites still use tables. Useing tables for layout is like putting ethonal in an unleaded engine only... it will work for a small amount of time however it break very shortly after. DIV is much more flexible.