the chances of sony going powerful are miniscule. have you not seen how much they made of the ps3 and vita, thier first time trying to be the most powerful (other than psp)? they made massive losses, not a penny of profit, that mixed with the fact that sony openly said they wont invest in ps4 much confirms ps4 will be weak and cheap like ps2 and ps1
I think you're looking into it a bit too much. The Vita hasn't sold horribly, it's been rather mediocre but that was to be expected since it was being released over Christmas when Monster Hunter 3G had just been released and the 3DS was going strong. Besides, just because they won't go for an absolute powerhouse with the PS4 doesn't mean it will be weak. I still expect it to be more powerful than both Xbox 720 and Wii U simply because that's how Sony does things these days. You have to remember that consoles are developed over a long period of time, so Sony wouldn't have time to completely rework the specs just because the Vita's sold a bit poorly. Apparently a Playstation magazine here in the UK got a hold of the PS4 and 720 specs and claims the PS4 is more powerful, of course you can't 100% trust it as it is a mag based around Sony's consoles, but it's likely to have some truth to it.