I personally have no plans to back port this to 5.2. Maybe you can convince Gail Badner though.

As for deprecations, we use them for very specific purpose. I get tired of explaining this - I really ought to just write up a blog post or wiki page about it and point there. The short story is that we use it to show users what they may be using that they should consider changing when they migrate to the next release. Here we know certain things will change in 6.0, so we do the deprecations indicating those in 5.2. That "policy" is not going to change - we have discussed it multiple times in the development team and there is an overwhelming consensus that this is the best approach.