For what it's worth....mousesavers.com's hot announcements is also saying it is RUMORED that the prices will increase this Sunday. Since it was the first Sunday of August last year and the year before, there is at least some logic to it happening again this weekend. Mousesavers' special link to
UndercoverTourist will save you a dollar or two more than their regular discounted prices. (and just so you know, Mousesavers' special link is not allowed to be posted on DIS or other boards at Mousesavers' request....you have to be a newsletter subscriber or know someone who is).
We have AP's, so I don't have to worry about this, but if I were planning to go between now and say the first quarter of 2009, I'd probably buy them this week before the price increase IF your personal finances are stable.
If my trip were much later than 2009, OR if your personal finances are a bit shaky OR if you have to use a credit card to finance it (meaning you won't be paying off the card before it begins accuring finance charges), I wouldn't buy now....instead I'd put that cash into an online savings account and get some interest on it.....that should about equal the increase, and honestly, with the economy going the way it is, there is every reason to believe that deals will be more frequent in 2009 from Disney (think about it....not many deals now mostly because those who were already planning a trip are likely still going, but read the boards to see how many are NOT planning that next trip yet). And remember, the best deals are usually on packages which means that you have to buy a ticket with it.....so buying now may exclude you from a package, or mean that you will negate your savings by having to buy another ticket. Disney (at least as of now) doesn't allow you to combine two tickets.
For what it's worth, the increase last year was only a few dollars. A 7 day increased $9 last year....a 10 day increased $10. Annual Passes (basic and premium) increased $14. Obviously if you need several tickets for your family it does add up, but remember that Disney will have your money now, vs it being in your bank account. With the economy tanking, and the future of the economy unknown at best, think long and hard about whether having that money in your bank account will benefit you more than having that money in a non-refundable ticket. If you need that money later will it be worth the savings if you have to borrow money or charge something and pay finance charges later? Online savings accounts earn 3%+...not a lot but better than most local banks or under the mattress pays....and in about 7-8 months should earn about equal to the projected price increase....but it'll be at your disposal if you need it.
If you DO buy it, keep it as safe as cash, because that's what it is.....unless you buy it directly from Disney's website there is NO WAY for Disney to trace lost tickets that haven't been activated....and even if you do buy it from Disney directly, there is no guarantee that they can/will replace it if it's lost or stolen. If it's stolen and used by someone else, Disney won't replace it, and you're out the money. If it burns/floods/is eaten by the dog....it may not be replaceable. So keep it safe from loss, theft, and destruction! Scan and save copies of the receipt and tickets to your computer, or at least put the ticket ID numbers in a separate place (address book on your computer or cell, take a photo of them, send copies to Grandma, whatever) to increase your chances of having them replaced if necessary.
Consider the fact that EVERYTHING is going up in price, and you're not rushing out to buy 100 pounds of hamburger to hedge the probable increase (I read this weekend we can expect food prices to rise by 4-8% by year's end). So consider how a Disney ticket is different from trying to buy ahead of the increase for necessities like food.
Ok...off the soapbox.
I think maybe we were all trying to be sure everyone compares apples to oranges. UCT is definitely loved around here, but if a true better deals comes along, I'm quite sure another company could share (or take) the love. 
