It's highly unlikely that a new piece of immigration legislation gets passed before the next presidential election, since all of the political horsepower will go into legislation that will look good to voters. Considering that the next presidential election is next year and the new president will take over the year after you're looking at least 2 years.
Even then I would wonder since the startup visa program affects so few people in reality. They have been discussing similar programs since the dotcom bubble and nothing came of it since it's a narrow problem to a narrow industry. I would be surprised if it ever passes.