Upgrading to an Intel Core i7

[PCDaddy]

I am new to these fourms, so please let me know if i posted this in the wrong place.

I know that the new Intel Core i7 has been released, and I am debating on whether or not to upgrade my entire rig to get the new processor. Currently i am using the Intel Q9550 (2.83 Quad). What would the difference in performance be against, lets say, the Core i7 920 (2.66 Quad)?

The reason that I ask, is that they are both 45nm, quad core, around the same clock speed, the core i7 is cheaper, both support ddr3, and the Q9550 has higher L2 Cache, yet the core i7 is supposed to be better.

Any help would be nice. Thank you