Yes, this release of Paymetheus is likely to be the last, or one of the last, Paymetheus releases. Efforts are being unified into development of the cross-platform GUI, Decrediton. Once that's ready, Paymetheus users can import their seed into Decrediton. A lot of developers have joined Decred and are actively contributing to Decrediton - it's being enhanced at a rapid pace.

In the meantime, this release of Paymetheus contains the updates for voting on DCP0002 and DCP0003 (Decred Change Proposals) and is intended as an interim release to smooth the migration process. Docs for DCP0003 will be here soon™.