Just because the number of legal positions is computed doesn't mean we're anywhere close to "solving" 18x18 Go, right? What's the utility of computing the number of legal positions?
"Because it's there."
The number of legal Go positions is a simply defined number that is easily approximated but an enormous computational challenge to compute exactly. I've made it my Mount Everest:-)
I also want to see if the number, written as 19x19 trits in ternary, corresponds to a legal position, which would be totally awesome (but at 1.2% the odds are against it).
I think that there's not much utility in this work beyond "it's an interesting challenge," but, well, there's not much utility in any game beyond "it's an interesting challenge."
81 * 2log3 ~= 128.38
Something like numberjack, which uses constraint programming for combinatorial optimization, would be useful and an article about how someone did this would be useful but alas the op is just a dull statement of a result and doesn't have much merit imho.
shuffles on, muttering