Too many items on desktop slowing computer?

Wrong. Too many items on desktop will slow your Mac down and increase the use of memory and CPU resources.

It will not slow you down. However, having a lot of programs running in the background will. There are two easy fixes for this. 1. Close them. or 2. Buy more ram. For $45 you can get 8 gigs in the macbook pro. http://www.newegg.com/Product/Product.aspx?Item=N82E16820233179 . This is assuming you have one that is less than 3 or 4 years old. It is easy to change out yourself but may void warranty.

Having too many items on the desktop absolutely WILL cause your computer's performance to suffer. Each icon on the desktop is drawn internally as a separate window, so many icons means many windows with a lot of calculation necessary to compute overlapping and decide what to draw and what not to draw. Having a few icons won't hurt, but if your screen looks like the stereotypical clueless Windows user's screen and has icons from one side of the desktop to the other, you'll have problems.

There are many other possible causes for performance problems, though. This is not one of the major ones. For more things to try, see the Mac OS X Speed FAQ.

Thomas A Reed is correct. I'm a big fan of desktop appilcations, but this can reduce the speed of your MBP. Increasing the RAM to 8gb will make your desktop speedier and performance smoother. Adding RAM will not void the warranty on mundane upgrades like RAM, and can be done in under ten minutes.