So dA does have an (rather limited, at first glance) API, which means developers (like me) can make cool things that would make viewing the site easier for users (you). People have been bitching about apps for years, but I don't think they really know what they want. So tell me. What, exactly, would you want from a "deviantART app".
The idea would be to offer functionality that isn't currently built in. I'm fine with the site the way it is now too, but some people would like to see changes or features that dA is not willing to implement for one reason or another.
All I want is a desktop app version of the chatrooms. Simplify the design, de-clutter the layout, make third-party scripts possible (like damn.ws, dAmngoodies, and autojoin), and looks sexy in general