There have been rumblings about the end of the Partner. So far, there have been no concrete announcements about it issued by Avaya. So, for now, its full steam ahead.
The Partner ACS still sells well for small outfits that do not need the complexities, costs or networking abilities associated with the IP Office platform. Yes, the IP Office can be configured as a stand-alone digital PBX, but the cost of hardware (for the IP-500) is still above that of the Partner ACS.
Still, even when the Partner goes, there will be new stock in the pipeline for quite a while and there should be support similar to what Avaya did for the Magix after it was retired back in 2006.
Discussing/speculating about the end of life for the Partner ACS is going off topic, so I'm ending my comments with this post.
If it ain't broke, I haven't fixed it yet.