Talking with the San Jose Mercury News, Denis Dyack argues "The 360 and the PS3 are equal in power in my eyes." He comments that the "PS3 has more processing power. The 360 has more available memory. It's pretty much a net, net."
Silicon Knights, the Canadian developer behind Eternal Darkness: Sanity's Requiem and Metal Gear Solid: The Twin Snakes (both for GameCube), is currently working on Too Human for the Xbox 360--a game that was first unveiled as an original PlayStation game in the late 90s.
On the topic of 1080p resolutions vs. 720p, Dyack said that 1080p and HDMI (which is standard on the PS3) cable interfaces have the edge, but both look quite good. "It is questionable if there is a difference between 1080p and 720p. All of our games are likely to be 720p because of the faster refresh rates. There are all kinds of trade-offs. It takes a lot more RAM to do 1080p. You'll reserve RAM for the textures. 720p is just less pixels. There is definitely a huge difference from 720p and analog."