Though Sony's faithful are familiar with this game and it has been reviewed highly in the past, I think that Ratchet falls into more of a niche market. I loved "up your arsenal" because it moved a little away from platforming and adding more first and third person elements. From the videos, the new game looks graphically impressive but I can't help but look at it and think that they have returned to their roots and "increased" the platformer components of the game. This may appeal to a broader audience than Up Your Arsenal did. For me, it's the exact opposite, though, because I hate 3D platformers. As much as this series and it's developers deserve it, I don't think it is going to sell extremely well early on. I'd be surprised if it beats out the performance of Heavenly Sword. As far as legs are concerned, I think it will have longer legs than some other titles because it is a rather unique game. Just my .02 of course.
I hate trolls.

Systems I currently own: 360, PS3, Wii, DS Lite (2)
Systems I've owned: PS2, PS1, Dreamcast, Saturn, 3DO, Genesis, Gamecube, N64, SNES, NES, GBA, GB, C64, Amiga, Atari 2600 and 5200, Sega Game Gear, Vectrex, Intellivision, Pong. Yes, Pong.