Graphically speaking the PS3 has the bump over the 360 period! How do I know that you might ask. Simple, the CELL CPU's SPEs can handle Texture, Mapping, Enviroment and other tasks that can be handed off by the programmer freeing the RSX chip to do other things. As a matter of fact, Sony originally was going to only use the CELL to do everything, Nvidea approached and offered the RSX chip. On the 360, their GPU will be doing all the work. That is why there will be graphics done on the PS3 that can not be done on the 360. Case in point, let me know when the 360 has a game like Motorstorm that has a changing enviroment that is never the same twice?
As for speed, there have been several articles posted , some from programmers themselves that point to the CELL having a considerable advantage because each SPE has its own memory cache and can act totally independent from the CELL CPU and the RSX chip. The 360's CPU and GPU share memory and bus. The seperate cores of the 360 do no operate independent from each other because of the shared memory and bus with the GPU. The PS3 CELL and RSX have their own bus. Gee, do I have to continue?
Both systems are set up to do HD so they both will do great graphics. However, the PS3 is setup to us a higher bandwith, deeper color set, higher bit rate and faster frame rate at 1080p simply from the inclusion of the HDMI 1.3. Sony waiting for HDMI 1.3 made this happen. Sorry, but I do not see how the 360 compares here.
And finally to dispell this simple misunderstanding. A single speed BluRay drive is considerably faster then a single speed DVD drive in the downloading of data on the disc. DVD slows down and speeds up depending on where the data is coming from on the disc. BluRay does not. A two speed BluRay drive is about as fast as the DVD drive currently being used on the 360. So please, if we are going to compare apples to oranges at least lets get our math right.