One thing we can all agree on is that when using such lo-res screens, GPU's don't have to work nearly as hard to produce great graphics like HD resolutions require.
I think the 3DS will have some quite impressive graphics that, while they won't be HD, they'll look just as good considering the lo-res screens...and the 3D effect is simply a cool bonus.
But it's still outputting to relatively lo-res screens, so just how much CPU/GPU power do you really need to make it look good and run well?
As for the underclocking thing.....Nintendo did that with the regular DS. The ARM9 in a DSlite is actually capable of 133mhz, but Ninty underclocked it to 66mhz. It not only saves battery life, it also helps the chips live linger by not pushing them too hard. They don't get hot as they run when underclocked....stuff like that.
I'm sure most of the chips in the 3DS will be underclocked, it's the Ninty way.
It really doesn't matter what the 3DS specs are, it's a new Nintendo handheld, it WILL sell many millions and we all know it. I just hope there's a better balance of games on the system this time......a little less kiddie and a little more cool....or badass if you will, you know what I mean? I also hope it doesn't end up flooded with a bunch of FPS games. They have their place, but we don't need TOO many. They need to try and maintain a good balance of genre's so it doesn't slip back into the "kiddie system" category like the DS has.