The ESPN pact enhances the Nintendo Fan Network, launched in 2007 by Mariners’ majority-owner Nintendo as a means to deliver information via an in-stadium Wi-Fi Network to the fans using their portable Nintendo gaming devices--even allowing them to order concessions.
One, I always forget that Nintendo is the owner of the Seattle Mariners. I had noticed how Seattle always seems to have more Japanese players than average, but I just chalked that up to being on the west coast. If the Cubs deal goes through (my understanding is that it hasn't yet been approved by MLB, though I could be wrong), the Mariners are one of only three teams to be owned by a corporation rather than a single majority owner (the Atlanta Braves and the Toronto Blue Jays being the others).
Two, I wonder how popular this is. I wouldn't expect to see a lot of Nintendo DS' at a baseball stadium, but there are 100 million sales worldwide, and once you've been to the stadium once, you'd bring your DS along if you had one.
I guess I have no real insight into this, other than thinking that it's rather interesting.
And you can now download the game off PSN and play one hour free, as long as you're a PS+ user (which still should be everyone who went thru the outage.) There's plenty of action in that first hour, enough to get a sense of everything.