I agree with PP, wait to see what the specials are for the time you're going. I know it's hard waiting. My friend and I were on edge waiting until the packages were posted for our travel. If you haven't already, check out mousesavers.com; it is a great website that has advice on saving money for Disney related stuff. I think they even had estimates of when past deals were released to get an idea of how long you need to wait. I think it was on a FAQ page.
If you're a Costco member, be sure to check their Disney packages as well. It's typically the same package (included TTMM and preferred seating vouchers) with some additional perks (for ours it was character dining and $20 gift card) at a lower price.
If you go separate, getawaytoday has good ticket prices. If you're only buying tickets from them, you don't have to pay the package fee.
We initially thought separately would be cheaper, but with the taxes added in, it ended up being a better deal going with the Costco package.