Hey All, I am a Travel agent, and I specialize in DW. In fact I only book group travel, the vast majority is for weddings. Honestly, this year has been the craziest year for DW groups. Out of Alberta (where I live and work) the flights to the major gateways are already sold out for April and May. I don't know why any travel agent would suggest waiting until now to book for a wedding, but I'm afraid you might have gotten some bad advice. In canada we always book our all inclusives as charter packages, with the tour operators that might only offer 1 flight direct/week. I know out of the US you will go for shorter durations which means you fly scheduled airlines, because of that it might be the reason they said to wait. Since it's not packages you're booking, it's the airline ticket only.
I always recommend booking the group 8-12 months prior to the wedding, and yes you're right, online the rates may not be in the system. The way it works is the tour operators give us an estimate based on the time of year, and what it cost the year prior. This is called Pre-registration AKA waitlist. So basically if you got a group quote 12 months prior and put your deposits down, and got your group in place, you are guaranteeing that your group can all travel on the same flight, to the same hotel, at the rate contracted. If when they do put prices out online they are selling it for less, the tour operator will match your group's rates with the accurate selling price for whomever within your group have paid their deposits. If it comes out and the accurate selling price is higher than your group quote, anyone within your group who has paid deposit will get to keep your pre-registered rate, but people booking later have to pay the new pricing. Then there are some tour operators that do offer the 1 time price downgrade, but only up to 60 days prior to departure. So if the rates are reduced after they are starting to sell online, so say 3 or 4 months prior to the wedding, then you can use your one time price reduction for anyone who paid deposit within your group, and everyone's rates come down. They will not do this for every sale and promo that comes out over the next year, and you have to remember that it's not just a holiday, it's your wedding. You're going to have to send rooming lists to the resort about 1 month prior, you need to organize your dinner, and set up your budget, so if all of a sudden within a few weeks of the wedding people start booknig because it's cheap, then it can kind of screw over your plans. Especially if you've been making OOT bags, and didn't factor in those last minute additions.
As for the rooms not being available at the hotel, and they are availabel with a tour operator - it's because tour operators buy a bunch of rooms so the hotel sells out, but the tour operators have the rooms in their allotment to sell in conjunction with the airline tickets. Buying in bulk is why the rates are usually better through a Tour operator than through a hotel directly.
Sorry for the long winded response, but I felt like I should explain how we can get rates prior to them being for sale online!!
I have been getting requests for wedding groups for April and May 2012 and I haven't had any luck finding them anything, and honestly the rates now are higher than had they booked in April/May 2011 for 2012. So it's unfortunate, but you have to book early!!!