More PR than anything. The way these things work is a press release is made off the back of regulatory filings. Market interest and chatter is gauged. Then the slow cogs of the SEC start grinding. Remember the "ARCA 24 hour trading" press release from a few months back? Yeah, we still dont have that...
Also note that there are 16+ exchanges in the US with protected quotes. And 30+ dark pools (ATSs). There are many venues to trade.