It means its going to press. No more work and copys are being burned. They will be in stores shortly, or as someone mentioned earlier, on warez sites soon.
If it is 100,000 copies then most big name publishers press and ship enough copies to go gold from the start. That's wild! ed: They should be measuring the number of units sold not the number of units shipped to retailers!
As PEST said, "GOLD" is the master cd used to make the different copies of the game for distribution.
This "100,000" thing you all are thinking about is Music if I'm not mistaken, and a gold record or album is ACTUALLY 500,000 in America. (It's MUCH less in foreign countries).
I dont know if Video Game sales even have this distinction.