Masahiro Sakurai, known for his work on the Kirby and Smash Bros. series, is suffering from repetitive strain injury in his right hand, according to a column that he wrote in Famitsu magazine.
Sakurai writes that his RSI has become severe enough that "it's starting to restrict my work and lifestyle...Using a mouse, keyboard or gamepad make my arm tired, so I can't use them in a continual manner".
The esteemed Sakurai suggests that he will be doing less digital communication and focus on verbal instructions. But digital communication cannot be completely avoided, so his solution is to use a trackball. Sakurai has experience with trackballs - they were used at HAL to create graphics and was also used to create Kirby in his Game Boy and NES titles. In fact, HAL produced trackballs for many 8-bit computers during the 1980s.
Source: [Polygon via Famitsu]