my 17" does this!
i just got my 17" PB Thursday evening. i had been using a mouse, but noticed this when i didn't have a mouse today for a little while. i will use the trackpad, and say i try to move the cursor from one side of the screen to the other, it will make it like 3/4ths of the way or something, then stop. i'll try to get it working again and it wont, but moving the mouse moves the cursor no problem during this time. i just have to wait like 10 seconds and it will respond to touch again.
like i said i just got it thursday, and it's my first mac and i'm loving it already, so it really sucks that it looks like i'm gonna have to bring it into the store and have them send it out already 🙁 . i'm leaving for a weeks vacation on tuesday, so i'll wait till i get back to bring it in.