The essays definately need some serious trimming, but it can be done. I am a new student admitted to the Fall 09 term.
In my experience the best way is to write your story, whatever you feel the adcom needs to know, your examples, etc. without worrying about the word limit. Then read and reread and decide what is the most important thing you want them to know. Also, try to get the point across in short, to the point sentences.(The limit is in place for a reason) If you have a piece of information in one essay do not repeat it in another essay even if it seems relevant, you want to use all the words to give unique information.
Also, remember the first 2 essays have a 250 word limit but essay three and four have a 500 word limit. So use the forth optional essay to convey information you cannot fit in essay 1 and 2.
Have friends/family review your essays, its easy for them to edit the essays as they are not intimate with the content.
Hope this helps.