The latest dev version of userplus now has support for Content Profile's required fields when adding multiple users. There are a lot of caveats, but if all your required fields are text fields (and they take one value), you're now able to use the add multiple users screen and have the content profile nodes created and populated. It's similar to what's been in there for required core profile fields.
If you've got required content profile fields that aren't text fields, then this is likely to blow up in a big bad way. If you're interested in getting support for other field types please post issues in the userplus issue queue.
This feature also works if you've got multiple content profile node types, each with some required text fields. If the required text fields are single-select with options, then this feature will also work. If the fields are multiple-select, ..., I don't know what will happen because that hasn't been tested.
Sorry for this advertisement, but I'm hoping for some free QA on this new feature.
- Marc