I think he has point. Mobile gaming has gone a completely different direction than a few years ago. Gadgets like the Ipone, Ipod touch, Android Phones and Ipad and other such devices offer alot more multitasking capabilities than the DS or PSP. The new Google Nexus S has 1Ghz CPU... thats pretty impressive for a phone. I think Sony should instead focus its publisher side and encourage developers under its umbrella to developers games for these devices.
On the other hand there is that rumor that Sony is developing their own Phone so who knows.