I do that too, but once I realized I could map the buttons in earthbound, I just added L/R functionality to the Z triggers to play more comfortably while using the Dpad.
As for a redesign, I don't see that happening until they make a successor to the Wii u, and that's only assuming they stick with the gamepad. Considering they didn't keep wiimotes as standard (is in the box controllers), we can't just assume they'll keep the gamepad for the next console.
If they do, a lighter version would work but it better be backwards compatible, should an original gamepad cease to work.
Plus, Nintendo isn't even selling the current gamepad separate from the console now, let's wait for that to happen before we talk redesign..