The new keyboard is clearly superior, at least in terms of feel under your finger tips. Just like with everything else Apple does that seems counter-intuitive at first, people will get used to it and then they will come across the old keyboard and wonder how they ever typed with such wobbly keys.
The lack of wobble is a clear improvement. The decrease in travel is the problem. It's just way too shallow. It's noticeably worse, and no, it's not just a matter of getting over it in the first few days for many people. There are lots of people out there who bought the MacBook and still dislike the MacBook keyboard months later.
I don't know about myself though, since the keyboard was enough to turn me off buying the MacBook, even though the MacBook was the exact form factor I had been asking for for years. The longest I've used it is for about an hour.
In any case, I need to upgrade my laptop, but I'm not wedded to a specific model right now. I guess the best way to summarize it is:
1) If the new 13" MacBook Pro or 13" MacBook has a superior keyboard to the 12" MacBook, I'll probably buy a 13" if it is Kaby Lake.
2) If the new 13" MacBook Pro or MacBook have the exact same keyboard as the 12" MacBook, I may just save my money and get a 12" MacBook when it goes Kaby Lake.
However, I'm still open to the idea of keeping my old 13" MacBook Pro for yet another year, despite the fact it is already 7.5 years old.