Hi there,
I know Airbus has certified last year a new TCAS mode for the A380 (other models in a very near future), an implementation in the Auto Flight Computer consisting of "managed" vertical inputs able to solve a TCAS resolution advisory.
The lateral resolution concept (TCASIII and IV), was introduced with the coming of Mode-S datalink, able to transmit both GPS coordinates and altitude, used by TCAS to provide a lateral resolution. Needless to say that every aircraft involved in a conflict has to be equipped with DL-Mode S. Anyway can find all you need to know in the following document:
http://www.tc.faa.gov/its/worldpac/techrpt/tctn099.pdf
As far as I know, it hasn't been certified yet ...
Regards,
fredgrav