The problem with keynote speeches, as distinct from the massive platform holder jamborees we used to get before E3 every year, is that you're really never sure what you're going to get. Sometimes you'll get a slick, finely stage managed presentation where new products are rolled out and demonstrated, famous developers stroll on stage to say 'Hi!' every five minutes and there are five different things jostling for headline space after the keynote.
On the other hand, sometimes you get Nintendo president Satoru Iwata talking passionately about his personal experience of getting involved in the games industry. Sometimes you'll get Will Wright rambling for two hours about the areas of science he's really interested in now, and how reading widely in different fields inspires him to create his weird and wonderful games.
And sometimes, like this week, you'll get Shigeru Miyamoto talking about his relationship with his wife.
Miyamoto's GDC keynote - his first in eight years - stands in sharp contrast to Phil Harrison's announcement-laden effort from yesterday. Only a few months after the launch of Wii, there was hope that Nintendo's creative boss would have revelations to share about the future of the console and its line-up.
However, if he had ever planned to turn GDC into a coming-out party for new products, that intention was stymied by Japanese stock exchange rules, of all things. A major transaction of Nintendo stock is currently being scrutinised, and any announcements which might affect the stock price are forbidden for now.
So instead, we got the keynote equivalent of a fireside chat from the man often styled as the Father of Gaming. He showed us a nice picture of his garden (the inspiration for Pikmin, doncha know). He told amusing anecdotes about how his wife didn't like games, and claimed to measure Nintendo's success at cracking the mass-market on the Wife-O-Meter.
He mused about the design process for the Wii controller, showed off a few wacky prototypes the firm went through, and prattled on proudly about his involvement in the creation of Kyoto's awesome Shigureden museum, which is devoted to the ancient Japanese card game of Uta Karuta (which is where Nintendo started out in business over a century ago) and uses Nintendo DS consoles and acres of plasma screens to bring the game to life.
For the crowd in the keynote hall in San Francisco, it was a mellow and interesting insight into the mind of arguably the world's most successful game developer. For people sitting on the other side of the globe hoping for a glimpse of something cool to play on their Wii in the coming year... Well, less so.
To give Miyamoto his due, he did manage to slip a couple of morsels of useful info in under the radar. Filtering through the chatter about game design philosophy, the direction of the medium, the joy of getting middle-aged ladies to play games and Satoru Iwata's tough love on team sizes and budgets, we can extract two key facts from the keynote.
Firstly, we're definitely going to be playing Super Mario Galaxy this year. We sort of knew that already, actually - but a bit of confirmation never goes amiss. There was a new video of it, which made people clap and cheer quite a lot. (Also, did you know that the infamous Mario 128 tech demo eventually became Pikmin? We vaguely remembered it from somewhere, but it's an interesting titbit anyway.)
Secondly, there's a major overhaul to the Mii channel on the Wii coming later this year. You'll be able to compare Miis with each other, enter contests and the like.
Aside from those announcements - if you can call them that - the keynote was largely devoid of news, but full of fascinating morsels about how Miyamoto designs games, and how Nintendo works internally.
He confirmed once again that the company's software teams have direct involvement in hardware design, discussing the conflicting attitudes within the company to the various Wiimote designs which were considered - the Zelda team, apparently, were pushing for more traditional controls - and his view on the Cube.
The points when he touched on the Cube were intriguing, actually. The console was Nintendo's least successful in many ways (not counting utter failures like Virtual Boy), despite a compact design, simplified controller and low cost, all aspects which the company has continued to pursue with the Wii.
Miyamoto acknowledged that the Cube was a step on the way towards the mass-market appeal the company now pursues - but he described it as "just a half-step in working towards an expanded audience" and complained that the controller was still too complex and intimidating for non-gamers.
On a related topic, Miyamoto also touched briefly on the thorny question of how to appeal to the mass-market and hardcore gamers alike - and those of you in the latter camp will be pleased to hear that he does understand that not everything on Wii has been to the tastes of traditional gamers.
Wii Play, for example, "seems to be too elementary" for hardcore gamers, he admitted - although he did point out that a lot of gamers like the game, because it's something they can pull out and play with non-gamer friends.
Animal Crossing, meanwhile, attracted an unexpected audience of hardcore gamers - which showed Nintendo that what people want "isn't always the best graphics or best audio or best production." Sometimes, just being fun will do.
Not the world's most informative keynote in terms of news, then - and perhaps not even the best of the traditional GDC "rambling about fun stuff" keynotes, either - but Miyamoto still got a standing ovation at the end, from developers and press delighted to have had a chance to hear about Nintendo's vision from the man responsible for shaping so much of it.
Oh, and for what it's worth - his wife has been converted. "If we can combat my wife, we can combat anything," he quipped. These days, she forgets to do anything on Valentine's Day because she's so engrossed in the Wii voting channel, and she's better than he is at Brain Age. She's one of us. Soon, if Miyamoto gets his way, everyone else will be too.
To read more direct quotes from Miyamoto's keynote speech, head on over to GamesIndustry.biz.