Your CPU is certainly not the bottleneck. However, I can just about guarantee what yours and most others bottleneck is: the hard drive. It is the slowest part of your system and you will notice much better performance, speed and responsiveness using Raid 0, 1 or 10. If you don't mind a high chance of losing all you data, then use Raid 0. Or if you want speed AND data safety, then use Raid 10, which requires at least 4 drives. And you can also utilize Intel's Matrix Raid if you want to use only 2 drives and get the most out of your system. What you do is create a Raid 0 for the OS/Apps, page file and scratch disk and then create a Raid 1 for storage. Or create a Raid 1 for OS/Apps and storage and a Raid 0 for page and scratch disk. I just did this for my boss on his Dell which came with a 2drive Raid 1. He uses InDesign and Photoshop and I reconfigured it to have a Raid 0 using the last 25GB of his 2 drives for scratch disk and page file AND email. He gets a large number of emails and Outlook was slowing down his system on occasion. He can't believe how much more responsive his system is now and can't believe it didnt cost anything. Now he wants me to upgrade to Raid 10 as he needs more storage and doesn't mind a speed boost.
RAM: unless you are using 3d and/or video editing/compositing programs, you don't need more than 3-4GB of ram. Also, you won't see any benefit to using 1066 vs 1333 or 1600 ram or even slightly better timings. There have been numerous tests and the most you could see is about 4-5% on the prior Intel 775 cpu's; but, now that the i7 has an integrated memory controller, it matters even less.