More than a few people have been alarmed since the comet flared up and can now be seen by the naked eye in your own backyard. Plus scientists still have no idea why the eruption occurred, and they don't even know what's in the middle of the thing. So you can be sure there's someone out there telling everyone it's an alien spaceship, and who's to say it isn't? Hopefully this doesn't mean the earth will be surrendering to the Comet Empire any time soon.
As far as Holmes colliding with us, unless you were planning to hitch a ride on the back of this thing, you don't have anything to worry about. Holmes orbits the Sun at 200 million miles out, which is a shade past our own 93 million mile orbit. Besides, if this thing was going to come anywhere near us you know that NASA has Bruce Willis programmed into their speed dial.
Incredible Comet Bigger Than The Sun [SPACE.com]