Because portables do more well in Japan, it's a huge market and even Sony has trouble. Nintendo is the king here and that won't change anytime soon. People who buy portables don't need Uncharted graphics, they need quality, fun, original gameplay.
I think they have more interest in the tablet market than the handheld market.
I was going to post something similar. I think mobile devices are going to take over the handheld gaming market as we used to know it, or at least damage it. --- I served 8, in war... my father served 23, in war... both of my grandfathers served, in war. WWII, Korea, Vietnam, Desert Storm, GWoT, etc. - ScarecrowES
The only way i'd consider it is if it was capable of letting me take my console games on the road.
Download my progress directly to the handheld (a graphical downgrade would be acceptable to me) and take that game with me. Then when I get home, upload my progress and continue. --- ~I was stomping goombas and saving princesses long before most of you were born.