One way the competition could attempt to mitigate Waymo's lead is to test and launch in areas where Waymo are not currently active (other states in the US, or other countries altogether). They could of course accelerate development of their self driving tech but that's easier said than done I presume.
I also worry Uber & Lyft's valuations and usage will drop with the introduction of driverless vehicles, unless they somehow manage to strike long-lasting partnerships with Waymo.
Regarding OEMs (i.e. car manufacturers), I can't tell what will happen with them: do they continue shunning Waymo and pursuing their own self-driving car efforts or come back begging for some sort of deal? I presume we will see both attitudes play out depending on how confident each company feels about its own self-driving tech ability and acquisition potential.
It's hard to foresee the consequences of this announcement, but I feel Waymo has upped the stakes tremendously today, and the pressure on everyone (including Waymo) to deliver is on, more than ever.