I "know" James now since August 2014 and all he is doing, day in day out, is coding, coding and bugfixing. On his own! He started the SuperNET project and within that project he started a lot of other little to normal projects, but all related to SuperNET. At one point even i thought that he wouldn't make it. Too many things here and there.
But i've been busy for almost a week now with building notary nodes and i must say, it is pretty damn impressive what he has achieved already. Everything is still related to SuperNET/BTCD only now i see finally the connection between all of his work of the past years. Yeah, BTCD got a new name and some things have changed, but that was mainly because NXT is following another path and James had to do something. And the outcome is very impressive.
So, about your question if he can keep up his word. I'm very sure about that one, right now. Check his Github and see there his work. Do you really think he would abandon his work now after 2 years of coding without even being on an holiday (as far as i know)? No, if there was a decentralised bet about if he would make it or not, i would place ALL my BTC's on YES.
There is NO doubt, for me, that he wouldn't finish this product. Or something bad would happen to him. That would be the only reason why this project wouldn't end, because it is too big for someone to pick it up and finish it.
Do not forget one thing. He codes this all alone! And for that he is for me one of the biggest coders of the world. Also a very n00b friendly one.
I'm in for Komodo and if you want my advice (you don't have to take it) then you should do it also.
https://blockchain.info/address/1P3rU1Nk1pmc2BiWC8dEy9bZa1ZbMp5jfg