Masahiro Sakurai has gained a reputation as the go-to man for some of Nintendo's key franchises that don't necessarily have Mario in the title. As a young employee at Nintendo he created Kirby, and has also masterminded the three entries in the Super Smash Bros. series, while also taking on the upcoming Wii U and 3DS title in partnership with Namco Bandai. His most recent release has been the critically-acclaimed Kid Icarus: Uprising on 3DS, so it's easy to see why he's earned the role of keynote speaker in his homeland.
The CEDEC event (Computer Entertainment Developers Conference) in Japan is, it must be said, a business-focused industry gathering. It's unlikely that Sakurai will reveal any footage or teasers about his current work, but is likely to talk more generally about his processes and development philosophy. With that in mind, it may be worth keeping an eye out for details when he gives his speech on 20th August.