Hi, all. A Kickstarter campaign has just begun for a new shield called DeDe (DEbug & DEvelopment). It provides quick visibility to the Arduino's GPIO using LEDs, and adds a lot of other useful features for debugging and development. I'm sure there are people here who would be interested in this sort of product, so here's the link:
Full disclosure: This isn't my project, but it was created by a colleague on mine.