* Upload csv user lists is not very convenient. Are you planning to
    come up with a easier/better system?
    What is not convenient?

I haven't played with the tool yet, but I would imagine that in certain
situations (e.g. the cohort is small, or the data is not being exported
from a database, or transcribed from a physical piece of paper), having
a text input field on the create cohort page that allowed a list of
usernames to be pasted in (e.g. from a wiki signup page) would be much
more convenient than creating a csv file.
(I imagine that once unified usernames really work, perhaps the
requirement to add the project name to the end of each line could be
eliminated and instead the project to produce metrics for could be
selected on the "Create Analysis Report" page.)

By the way, does CSV here mean any CSV or is it picky about what kind of newlines, separators, field quoting and encoding you can use? CSV is a rather poorly defined format, it's quick and dirty but easy to mess it up.