DF is pretty likely to see a 1.0. It may seem far in the future, but Toady's been on this for ten years, so it's not super likely that something will change the plan now.
These sorts of threads always miss the point:
"Version 1.0" is an utterly meaningless metric.
Version 1.0 means "all the core goals are complete". The new design plan doesn't have 100 core goals that we the players know about, and it's presumably subject to change. But it does exist, and the basic stuff that it contains is more or less the same as the old system.
Toady has said this is his life's work - when he finishes "1.0", he will just keep working on it, adding more things.
He's said he'll probably do that, but he's also said he may work on other games. I don't think he has a super defined plan that far out, but I'd imagine he'll do both of those things.
Toady could declare the very next version that comes out "1.0" if he wanted to, he could also keep working on version "0.132.01" at his death bed, since the entire version number mechanic is arbitrary, and the only thing that matters is that the number keeps going up - he's even rewritten the criteria he uses to measure version numbers before, he could just as easily do it again.
If, instead of asking about "1.0", you are asking when DF will be "finished" or "perfect", and Toady will never again touch the code, then the answer is probably "not even after his death", as Toady intends to keep working on it, and after he dies, let it go open source, so future generations may be able to pick up and improve on DF.
That was a book keeping change. He still intends to complete more or less the same things before 1.0, although I'm sure there are some changes, and there's a change in the system in that some goals have different weight with regards to version numbering. But he still, now as then, intends for 1.0 to be one core increment up from 0.99, which is also when all of the main goals are complete. That hasn't changed, and although I expect he'll probably rejigger the specifics of the core goals in the future, I wouldn't expect the sort of huge change you think is possible.
Dwarf Fortress will NEVER reach a 1.0
Not because it won't ever be done, but because that's not how Toady numbers his versions. Consider the current version "V 24.07"
No, it's 0.34.07 actually. Look:
http://www.bay12games.com/dwarves/ it's in big yellow letters on the head of the index page and everything.