Ok, since I am such a nice guy, I will clear things up for everything...
Yes that is a Core 2 duo, but that CPU uses 1033 FSB. Intel is trying to push 1333 FSB. How are they doing it? They are only lowering the price of the 1333 FSB. In other words, if you are purchasing a E6700 (on a whole new computer from a store), you are a sucker.
Far from simple.
The 8300 (128MB) has a better architecture and I am sure operate faster. You could have a video card with 2048MB of ram on it and it would not out perform a 256MB video card with much better architecture, speed and design.
Yes it does. But 4MB is nothing, almost any Intel CPU over 200$ (if not 150$) will have a 4MB L2 cache (2MB shared). Some even at 8MB (quad). We will also soon have 6MB shared on duel cores (wolfdale). (edit: and 12MB on the Quad)
Short explanation on the whole GHZ things: The reason why your old CPU has a higher GHZ is, you guessed it: the architecture. One of the factors (without getting technical) is the pipeline size. Basically the pipeline allows the CPU to work on several instructions at once. The deeper the pileline, the more instruction it works on, and in turns technical the faster it works. P4 (24 deep I think) was built around that. AMD came along and made a better architecture with less, Intel copied them with the Core Duo 2.
http://en.wikipedia.org/wiki/Cpu (go down to Parallelism to read up on pipelines)
OK, so, to sum it all up: That new CPU kicks the ass out of the old P4 EASILLY, but there are currently CPU on the market right now that are cheaper for the same performance.
On top of this all... Intel is brining out a new CPU built in 45nm (penryn) vs the 65nm chips. This means less electricity, faster chips, and with some improvement (like SSE4).