In my opinion, they need 3 things:
1) Maintaining quality and quantity of their main IPs, specially in launch window.
2) Hardware capable of supporting 3rd party games with ease and relative parity with other 2 - this one is no-brainer really, since 3rd party games are a must in this day and age for any platform.
3) Kid oriented games - Nintendo already promised more focus on this, and considering what they've shown in E3, I'm glad to see them deliver. I think that lot of people underestimate how important is this to gamers who have children when comparing two platforms with similar capabilities.
Of course, few additional IPs that are oriented at western gamers would be also helpful, specially if they get there hands on some western RPG developer.