The reason it says nothing on success is that it follows the general philosophy of programs on Unix. Of course, there are exceptions, but it's not obvious that pyvenv should say anything, and what it should presume is the user's next likely step. As well as running the venv's Python, any script in the venv should be immediately invokable (and call up the venv's interpreter). At the moment, that's just pydoc - but that might change over time (I originally had pysetup in there, before packaging got pulled).

AFAIK the activate script shouldn't have the executable bit set, so it shouldn't show up in e.g. autocomplete results. Note also that the activate script is bash-specific, so it may not be wise to mention it in cases where the user's shell may not be bash or a compatible shell.

It's assumed that third party tools will build on top of the existing venv support - for example, in the absence of packaging, venvs will need distribute/pip in order for users to be able to install stuff into them. These will likely provide the visual feedback required (e.g. before merging into CPython, the pythonv version of pyvenv installed Distribute in the venv, which showed that something was happening).