It's still not a true Gmail app (sigh), but it's a step in the right direction, we suppose. Google has today announced that it has released an experimental user interface for the iPad built on the Gmail for mobile HTML5 web app, but unlike the iPhone and Android versions, this one has been retooled a bit to best take advantage of those extra pixels. iPad Gmailers will find a two-pane view with their conversations on the left and messages on the right, and while it's not exactly revo