The prices that they have on the website for the year 2010, Is that the cheapest the cruises will be, or will they get higher the closer it gets to that particular year?
That would be impossible to say. The prices go up and down depending on demand for a particular sailing. Carnival will protect your price if it goes down. They actually adjust rates several times a day on some sailings.
It is is better to book early and get your cabin choice locked in. If the price goes down they will adjust the price, or refund it to you, and/or issue an On Board Credit.
My 7 day cruise has dropped from $569 to $349 before taxes. I have 1 refund, and 3 OBC's. All that and I still have my original cabin.