EUPL, a weak copyleft license that closes the SaaS loophole, OSI+FSF approved (joinup.ec.europa.eu)

In my opinion, it's a perfect replacement for LGPL, EPL, and MPL to ensure SaaS users are covered by the terms of the license.

Agreed. There was a debate on the point "is the EUPL strong or weak copyleft?" It is not "strong copyleft" as the FSF conceives it, simply because European Law excludes license "viral" propagation in the case of linking (under any license, as soon the European law is applicable, which is always the case for the EUPL).