We (CEWG) are in talks with Linaro to see how we can collaborate on this. Linaro is doing some great work, which we would like to of course leverage. Hopefully, we'll be able to pick up some things from CE vendors that they wouldn't otherwise get, and get those into their tree. I'm hopeful there will be lots of code exchange between the two projects. But we'll have to see how quickly they move on to another kernel version.
Linaro has a pretty aggressive upstream-first policy (which is good, but it keeps them constantly moving forward). The version gap between what companies are actively using in their product and mainline is precisely what LTSI is targetted at bridging. I can imagine LTSI pulling features that Linaro has pushed to mainline.