Unless Sony has some killer feature in the NGP or a must-have title, they're not going to dent the Nintendo juggernaut, no matter how overpriced and arbitrary the 3DS is. I'd call it the second coming of the Virtual Boy but it actually performs like it's supposed to.
Besides, when has bashing the competition ever helped sell something in the history of the industry? Not often, that's for sure. The mid/late-90s Sega Saturn commercials come to mind... they dropped a PSX off a building, "Fly PlayThing, fly." And there was one of riflemen launching a Nintendo 64 into the air and shooting it. Hell go further back. "Genesis Does What Nintendon't" anyone? They weren't doing too well with that until the original Sonic came out.
Lump Phillips, the original Atari, 3DO, and Neo-Geo into that group with Sega and you should have a prime understanding of what NOT to do with your products.