I've had good success with it in several applications:
1. Compost pile. I throw EVERYTHING in my bin so I like to ensure that the pumpkin seeds, disease organisms et al are completely composted - when my bin is 'cool' and needs kickstarting I'll add some molasses and it immediately goes very hot and stays there. Also handy when I am out of room in the bin because I just got a bunch of new materials to add. 20 pounds or so of coffee grounds from starbucks and a couple gallons of very dilute mollasses (maybe a cup per gallon of h20) and viola - inferno time.
2. Because sadly, some organics smell like what they are. I've had odor issues when spreading chicken manure, too much cgm, Milorganite and other products that I have had great success with. Since I live in a very nice, upscale subdivision with neighbors who aren't in love with the smell of poop I find that if I add a couple ounces of molasses to a 2G pump sprayer of water and spray it around the 'ripe' fertilizers the smell goes away within a day. I also spray molasses on the yard whenever it occurs to me that I haven't in a while. 3 years ago when we bought this house the yard war horrid. I immediately spread a truckload of the Plano composted top dressing, I use organic ferts and I spray with molasses. I do nothing for weeds and bugs except pull the former and avoid the latter. After three years, our soil is very good, loaded with worms and the grass clippings break down immediately. We had two fire ant nests this year, our neighbors consistantly have a LOT more of them.
3. Dog poop. I just never have developed an affinity for the task of scooping poop. I have 3 dogs and very little area for them to poop in the back due to the pool/patio so about once per week I put the little brass 'pressure nozel' on the hose (Lowe's, around 2 bucks) that turns my hose into a decent pressure washer, I spray the piles to break them up and then I spray a mixture of molasses and compost tea over the remainder. In the summer this gets rid of it in a day or two, in winter it is slower but I find the frozen or freeze-dried turds less offensive to scoop.
4. Veggies. IMHO the problem with most tomato gardens is too much vegetation and not enough fruit production. I've been working a lot of molasses into the beds because the potassium and other minerals seem to help with this.
How much it helps with fireants and fertilizing is an open question - I may just have a nice balance going without it. For heating up a compost pile, getting the 'stank' out of a fresh application of Milorganite/CGM on the lawn and breaking down the puppy piles I am certain that it has been effective because there is an easily measured difference before and after.