Lol, Easycor is partly right... never ask "when".
What we're doing for the BoB Event is building the terrain in the AH1 TE, with standard everything... meaning standard fields, standard strat, standard tiles. HTC has a converter that will "update" any standard terrain into an AH2 map (there might still be manual tweaking needed to be done by HTC, I don't know yet) but it only works on a purely standard map.
And that is all I know about it so far.