Well all that's happened is the Republican party of Texas has adopted the issue as a plank in the party platform. So the next step is for a House and Senate member to introduce legislation in their respective chambers once the legislative session begins next year, which will certainly happen. Then the bill will go to committee for approval. This is where the previous bills have died as it is the committee members who decide what bills to address. Then if all goes well and it makes it out of committee, the bill is voted on and sent to the other chamber for approval. Presuming some version of the bill is approved in both chambers, the bill will go to Gov. Abbot's desk. Last he spoke about the issue he was for the status quo, so he could veto it. If he signs it next session the law could go into effect Sept. 1, 2017. I wouldn't be surprised of it's pushed back to Jan 1, 2018 or even later as a concession to the dealer groups in order to make Model 3 deliveries as difficult as possible.
As far as a state tax credit for EVs like California or Colorado have, don't hold your breath. If you think the dealer lobby is powerful, you cannot fathom the power of the oil lobby.