Based on this thread, CAT as it currently stands won't be receiving any new major updates or new features. This is very unfortunate because CAT is a great concept and it's extremely powerful and there's nothing else really like it on the market. There are some 3rd party tools for 3ds Max such as InstantRig and LH Auto-Rig that replicate the modular rigging of CAT, but they don't have the extensive animation tools. Likewise, most other 3d packages don't really have an equivalent--Cinema 4d has CMotion but that doesn't have all the other great features like foot placement, motion extraction node, etc.
The problem with CAT is that it's a bit outdated. It's buggy in places and can cause crashes. Some things are counter intuitive--for example, Motion Extraction Node is a broken mess unless you select the pelvis and enable "Additive to Setup Pose" in the Link Info, then it magically works for the most part. The interface is dated and clunky. CAT could use additions like an equivalent to Biped's Motion Mixer--manually blending animation layers in CAT is well and good but it's not the same as a timeline editor. CAT can also be slow when working with multiple characters.
So my idea is, if it isn't practical to give current CAT a major overhaul, then build a new version of it from the ground up. Completely new codebase. Something that basically does the exact same thing as CAT and has similar features (CAT motion layer, adjustment layers, motion extraction, etc) but does so with a fresh, clean, and modern codebase that can be maintained and regularly updated. Something that can have a slick new interface that meets the needs of modern animators. Something that can take the lessons learned from CAT and Biped and expand on them and improve them. Something that can be designed from the ground up for modern hardware and make use of multi-core processing or even GPU processing.
One benefit is that this could be a way to unify the character animation systems of 3ds Max and streamline the workflow and interface. Right now it's disjointed, fragmented. First you have the regular bone system which has a bunch of tools. Then you have Biped which has its own set of tools. And then you have CAT, which also has its own set of tools. But then they sometimes share features/concepts using their own implementations (animation layers vs biped layers vs CAT layers). This makes animating in 3ds Max a bit rough or confusing for newer and younger users since there's so many systems to learn, each with their own pros and cons.
Another benefit is that this could provide a framework to more easily add other modern features later down the line in future updates. For example, maybe the new tool could get built-in lip sync in a future update. Something similar to FaceFX? What about something like Clovis Gay's F.A.S.T. plugin for 3ds Max? Maybe the tool could get a node-based scripting system like Houdini to allow for procedural animations beyond CAT motion layer. Maybe a built in crowd system? Maybe the ability to script AI so animated characters can "react" to stuff without the need for manual keyframing? What about a timeline editor like the one I suggested here?
I'm just spitballing of course, but you get the idea--stuff like this could potentially be added in future updates, which may or may not be practical with current legacy CAT.
So to summarize, make a brand new rigging/animation tool, CAT 2.0 or some other name, built from the ground up to take all the good stuff and lessons learned from CAT, Biped, and bone system, and which can be updated regularly. One centralized system to rule them all, which can be the sole focus for future development.