I can't wait. Ever since reading the codex entry for Earth and driving the mako on the Moon, I've wanted to visit Earth. It's a pity that by the time I finally get there it will be a war-torn wasteland.
I just finished off a third playthrough of ME1/2 with an all-Paragon FemShep that saved the whole team... except for the crew, they all died. I plan to do one more before ME3 comes with an all-Renegade ManShep that gets almost all of his crew killed.
I, for one, cannot wait to lead an interstellar taskforce comprised of turians, salarians, asari, geth, krogan, quarians, and rachni in a bid to defend Earth.
Hmm. In my main game I let the council die, so I probably can't count on the Asari, Turians or Salarians. And I took a neutral stance on the Quarian/Geth conflict, so they might be busy killing one another by the time of ME3. I did save the Rachni Queen and the genophage cure, so I might be able to count on the Rachni and Krogan. So I'll be saving Earth with the support of a small group of nearly extinct aliens, and aliens that enjoy killing each other.
Earth is doomed.