Re: My New Build...
First off, if you want to use the i7 core you will need a new motherboard with a 1366 socket. These new sockets only accept DDR3 memory so you will have to shell out some money for that. i7 core is a quad-core, sort of. It is a brand new architecture that has the memory controller embedded on the die and does not have a FSB. It has some new institution which I haven't read up on yet. The i7 core also bring back the good old Hyper-threading which essentially creates a second virtual core for every core that uses it. When you do the math the i7 core has actually 8 cores. Because the FSB has been "eliminated" the memory botttleneck also has been eliminated, but to a certain degree. The new institution I was telling you about earlier does cap the memory, but at much higher speeds. Overclocling with the i7 should also be better.
edit: The reason I didn't suggest the C2Q or the i7 is because web-apps, music, and gaming won't make full use of 4 cores let alone "8". It wouldn't be worth it for you to spend the extra $400 dollars on the CPU, a new motherboard, and DDR3 just for the extra multi-threading because you won't use it. You will be better off with an E8600 which is clocked at higher speeds and costs far less. The bang for the buck is far better.