It seems that the first step in getting Jupyter to know about a new version of Julia is to do Pkg.add("IJulia") in Julia. Except that that doesn't work; it seems that now you're supposed to use some special pkg mode in the Julia REPL.
So, I hit ] to enter pkg mode and type "add IJulia", which seems to be the appropriate thing. It churns a bit, tries to build something called "Conda" (which is apparently the dependency-management bit of Anaconda, the Python distribution thing), and gives me an error message that starts like this: "ERROR: LoadError: ArgumentError: isdefined: too few arguments (expected 2)" followed by a stack trace whose first and last entries are "top-level scope at none:0", which doesn't exactly help to nail down where the problem is.
Related operations like "build Conda" and "build IJulia" give similarly unhelpful error messages (some of them enjoining me to do things like Pkg.build("Conda") that so far as I can tell don't actually work at all).
Do I just need to wait for release 1.0.1, or is it likely that I've done (or left undone) some unfortunate thing, that I could fix and make everything work?