i hear what your saying, but the problem with that logic is that your using what we currently know about tech that is released and known to the public to make a decision. Did we know a year before the PS3 was released what the capabilities of the cell processor were? no. Take any console for that matter, a year before release, we've never known what it could do or the hardware that would be used.
I agree with crazyeyes as well as a couple others on the possbility of the PSP2 having PS3 like power. Just bc they state PS3 power, doesn't mean PS3 hardware. There's been plenty of time since the PS3 was released(5yrs) to work on architectural changes+node shrinks to lower the voltage requirements and thermal output, or what i personally believe, that there's been enough time to research into developing a newer more advanced+smaller processor that at lower resolutions could have the horsepower to drive graphics as appealing as a PS3.
When it comes to new technology we need to be more open minded, you can't base future tech releases on tech that's already released, if we did then we'd never move forward. Its called innovation and creativity, something that big companies like sony, nintendo, intel, AMD, Nvidia etc excel at.
EDIT:Not to mention there are many programming tricks/techniques that can make renders seem better than they really are because our eye's aren't good enough to register the differences. There were even articles released on AMD/Nvidia writing drivers to render games slightly differently in attempt to raise performance yet the visual difference was negligible