Hope this will be integrated soon!

I wonder if this project has died and should be forked to carry on..

Yes it seems it has died and now you can use:
https://github.com/FasterXML/jackson-module-scala

I'm also taking a look at the Zeebox fork: https://github.com/zeebox/jerkson/ - seems to have been ported to 2.10, didn't test it yet, though.

Now, this [ABANDONED] flag in the project description bothers me a whole lot. At least there seems to have a ton of forks, just don't know which one to trust =(

And another good-looking option: https://github.com/wg/jacks - which I also didn't test yet :P

As this is now a list of alternatives, I'm trying http://argonaut.io/

Argonaut seems nice and has Tony Morris (Scalaz) as developer so I guess we can expect some quality.

I use this one:
https://github.com/FasterXML/jackson-module-scala
It has a good support from the author and works fine in production for my case.