With the latest release of rsyslog (8.11.0) we have also introduced a new set of packages that we will produce from now on. We have now added rsyslog release packages for Ubuntu Utopic, Vivid and Wily to the list. Thus, you can now use the packages made by Adiscon on newer Ubuntu versions, too, even on the upcoming version.
And, new releases get a package shortly after the official source release, so you can easily stay up to date with rsyslog on a larger variety of Ubuntu distros. For now, we will also keep making the packages for Precise and Trusty.