Barnes & Noble's PubIt! self-publishing conduit has been active for well over two years, but you'd be forgiven for overlooking it with that somewhat forgettable (if very emphatic) name. The company might just know what you're thinking, as it's giving the service a considerably more memorable title, Nook Press, while upgrading features at the same time. Although the royalty structure remains the same, Nook Press now incorporates a web-based authoring tool: would-be Hemingways can write and preview t