An aerogel sleeping bag would be very interesting in terms of loft (warmth) for the weight. Durability is one concern - mountaineering gear takes a lot of rough treatment. A particular kind of durability is important: compressibility. I frankly don't care that my synthetic-fill winter bag weighs a quarter-pound more than my down winter bag, I care that my down bag takes only a quarter as much space when stored in my backpack. (The synthetic bag nearly fills up my largest pack, leaving almost no room for such minor items as food.) You'd want it to compress easily, loft out fairly quickly without special effort, and remain compressed for weeks without losing loft (e.g., when travelling to a big mountain, you don't need the big bag 'til you get there.) A few hundred compression cycles would be a good test - that's like a few years of use.
Don't know what your manufacturing costs are, but you could charge a premium just based on the high-tech cachet of the material. To survive in the market, though, you'd have to also get the shell right. Got to be strong, light, not too slippery, water-resistant, ideally wind-resistant and breathable; come in the right shapes and sizes, etc. The fill is only one part. Then you've got to make sales... you might need a partner.
Several of us here on SP have contacts in the outdoor gear industry, if you're serious.