I agree, I miss it so much from < Opera 12. However there are many things that are as great of importance for the devs to dev on.
I reckon that it's going to be at Chromium development to lay the groundwork - to which other clients can start to build better tab handling. It might be a good idea to post feedback to Chromium devs (google-groups, email, twitter, etc).
Here's Chromium blog: blog.chromium.org