I'll be curious to see how it does.
My guess is that a lot of people have invested in Kontakt and 3rd party libraries at this point. In such a case, you don't just switch samplers - it's almost like your DAW software. It's not like replacing one MiniMoog emulation w/ another.
Sample Tank was a blessing back in the days, because it filled the gap and offered good quality libraries that covered the basic and the some. But nowadays, many DAWs offer great sample-based instruments, and the basic bread and butter are often covered quite well.
I know that personally, I have no use for yet another bunch of "good" instruments - I'd be more likely to invest in specialized 3rd party libraries.
For drums and percussions, there are lots of dedicated options like BFD and SD, which will always have the edge on an all-in-one package imho.
I don't know - I mean, unless ST actually comes w/ a piano that's better than anything out there, basses that rival the Scarbee stuff and such or unless they get massive support from 3rd party developers, I'm curious to see how it'll do.