The Genesis Project, an Adobe blog, has details on the Adobe Mercury Playback Engine, the GPU playback engine demoed at IBC in September and mentioned a few weeks ago on another Adobe blog which discussed Premiere Pro "Next".
Again, check out the details in the Q&A, but you won't find the phrase "After Effects"!
If you want After Effects to be a better finishing tool, then make a feature request at the Adobe website.
Update: Karl Soule has a coupla posts too, Three words you'll be hearing a lot of: Adobe Mercury Engine and More on the Mercury Engine...,
"we do have external people testing it out now, including some people posting over in the RED forum here. As soon as we have any information about availability, I will be the first one to post it here."
On the RED forum, Adobe's Simon Hayhurst says,
"On topics like TC, Grading Integration, RED Rocket™ --- all important stuff .... and we're continuing to knock these kinds of items down one by one. Prioritization of which order to do them in is the hard question ..... Mike Kanfer is our most active Red forum participant and your first port of call for prioritization opinions.
On the topic of AE and Mercury --- the engine in AE is very different to an NLE engine --- there is inevitably some tech cross-sharing that can be done, but the apps work in very different ways at their core, so much of the core rendering engine needs to be different"
Update: note that the RAM base of the approved graphics card will effect performance (how many clips at what sizes and number of filters applied), so if you're doing RED files you'll want the more expensive cards.