Did you thoroughly check the blog LL put out about Mesh?
EDIT: From the blog post, "Although we cannot share these details yet, we will continue to keep you informed on our progress and other relevant news on this blog."
That might include your question under the umbrella of "to be released".
Yes!!!! I would love to see it become a default for SL viewers, it just makes sense
Its convinient, easy, and just awesome to be able to double click and tp where you want (unless theres a landing point on the sim/parcel )