I am looking to buy my first Mac. I wanted to get it before Christmas, but after hearing some rumors about there might be revisions to the powerbook line at MWSF I am skeptical about ordering before Christmas. What do you think the chances are of revisions in the 12" PB line? Also, is there any type of sales exchange thing that I could return my order within a certain amount of time? I am going to custom order my PB online with an educational discount.