Now there are two reasons to change Apple's generic OS X 10.7 wallpaper to a custom one: it's a fake. A professor of physics spotted Apple's source, which was astrophotographer Robert Gendler's image of the Andromeda Galaxy.
As you can see from Gendler's photo above, and Apple's wallpaper below, there's been a big Photoshop job undertaken. Many stars have been cleaned up, and a whole galaxy, the M110, has been obliterated. This may be an obvious thing to say, but isn't Gendler's image so much more beautiful? If you take a look at the moving gif on Boing Boing's website, you can see the differences between the two and let me know which you prefer too. [Robert Gendler via Boing Boing]
Update: In case you missed EvaAchelous' comment below, the M110 galaxy shares the same string of alphanumeric characters as Samsung's Galaxy S phone, the SHW-M110S. Considering the two have been fighting it out in court over some infringements concerning the Galaxy Tab and a few other Samsung phones, this is one conspiracy theory which could run and run.