The second Nokia patent Unwired View's dug up this week apes the Nintendo DS more than the Sidekick. It's got two screens, one touch, the other for visuals only. It also has the quickly becoming standard intelligent layout, which changes depending on the angle the phone's opened at.
When it's flapped completely open, the split view coalesces into a single one spread across both screens. Even if the concept isn't wholly inventive by this point, the second screen could set it apart from the million over phones now jumping on the touchscreen bandwagon.