In an interview with Playstation: The Official Magazine (reported by IGN, Sony Worldwide Studios' President Shuhei Yoshida, admits that Sony are "having a more difficult time than [they] had anticipated in terms of getting support from third-party publishers, but that's our job."
He also states that Sony are very happy with the platform as such. "It's an amazing gaming experience," he stated to the magazine, but he also noted how the growth of other gaming sectors were hurting PS Vita: "because of the growth of the social/mobile sector, lots of opportunities are being presented to publishers to choose from, and because the social/mobile side is the growing sector in terms of the business now, they are very quickly shifting their development resources to be part of that growing market."