Have just uploaded a build of the custom BPM worklist sample which is built against BPM 18.104.22.168. You can find the download links and JavaDoc on the main worklist page. The code is available in the subversion trunk (for now) or tag VERSION-1.6.
This is basically the same as the last version of the sample, just recompiled for the new release of BPM. I am planning to add some significant new functionality to the sample to coincide with BPM 22.214.171.124.
I am also working on a C#/.Net version of the worklist. See some details here if you are interested.