I know this thread is a bit old, but I thought I would weigh in as I manage the Specialty Foods section (Cheese, Beer, Wine, Olives, Coffee) at a local health-food/gourmet store. We cut tons of different cheeses...everyday.
The only cheese I can think of that we never try to tackle with the wire cutter is Parmigiano Reggiano (due to its massive size and crazy-thick rind.) There's just no way to break through that rind with a wire cutter. We take a trio of medieval torture-looking tools to score it all the way around and literally crack it open and break it down from there into appropriate sizes.
Anyway, we rotate between a pair of wire cutters 99% of the time and occasionally use some dedicated "cheese knives" like the ones pictured earlier in the thread with the gaping holes in the middle. There's also an interesting knife I've used a handful of times that is both extremely thin and short, but with a normal sized handle. These dedicated cheese knives really are only good when cutting soft cheese (soft-ripened, creamy, chèvre, etc) but the cheese wire works better most of the time.
We use a 10" German-styled chef's knife a good bit for trimming pieces (mold removal) for repackaging and for sampling of any cheese that isn't super soft. It really depends on the particular cheese you're working with and how thin you're trying to cut it as to what the best tool is, but again, you normally can't go wrong with the wire unless you're just doing something crazy. Some cheese is just impossible to slice very thin by nature.
My point is, if you were to make the perfect custom cheese knife, I don't think it would be a knife, but instead some variation on the cheese wire cutter. My 2 cents.
Below is a photo of the cheese cutter we use. Next picture is the thin and short-bladed knife I referred to, and below that is someone knee deep in cracking a wheel of Parm open!
I think cheese and walnut go very well together 
