From reading the novel that I picked up from Walmart, The Doctor, a bunch of other Constructicons went down to where Megatron was located. Long Haul, Scrapper and Mixmaster destroyed another unnamed Constructicon and use his parts to build Megatron. Then the doctor inserted the shard of the allspark into Megatron and he was rebooted.
From the sound of the novel, Soundwave won't even make an appearance on Earth. We'll probably see him on the Nemisis but so far there is no indication he landed on Earth and blasted any autobots. He's just up there collected data and transmitting it. I hope that's not all what he does.