I don't really think Japanese gaming industry is in trouble, they are selling the same they are used to sell, but West market got much bigger, so Japan look in trouble now...
Anyway, I have some ideas to make Japan gold time come back, put yours too.
-Put english subtitles options in almost every game, many anime fans would like to import they're favourite anime game or many games have better dubbing in Japanese than in English or even would like to play that games that we know for sure aren t coming officially to West.Mainly small publishers that don't have how realesethey're games worlwide. In other worlds, estimulate players from others regions import games from japan.
- Western devs. should invest more in Japan, i think that a western game never sold a million in Japan alone. Make more advertising about they're games, estimulate the niches for shooters, rock games, movie games and this stuff.
-Making more high budget games, if you look to the japanese chart most of the games are too economical, West is full of high-budget in top games, the only ones in japanese chart i THINK are Dissidia:Final Fantase and Monster Hunterand i'm not sure!). Japanese chart is in need of Top games.