There is nothing certain about the Gold Master release being the final thing. Gold Master is more of a release candidate, if everything proves to be alright it will become the final product but if there are some quirks needed to be resolved there might be a Gold Master v2.
If Mac OS X Lion proves to be pushed back another week it might just be because Apple decided to solve some last minute issues making this Gold Master version obsolete.
There is no way to tell before we get the final release, or Apple releases another Gold Master version to developers. There is no denying that Mac OS X Lion GM has it's problems so another version wouldn't really shock anyone, would it?
RamGuy -
You're correct in that anything could happen (i.e. a second GM release);
However, if you look at the history of this, this is exactly the same stuff that we went through when Snow Leopard came out; everyone was clamoring for another GM release; that GM Release was 10A432 and had its fair share of bugs. 10A432 ended up being the retail version; Keep in mind that another GM release of Lion would require the schedule to slip by another 2 weeks at the least. Also, when you look at the history of things, Apple almost always gets the 10.x.1 release out within a few weeks anyway of 10.x.0 coming out.
Snow Leopard (Original Release = 8/28/09, .1 Release = 9/10/09 -> 13 days)
Leopard (Original Release = 10/26/07, .1 Release = 11/15/07 -> 20 days)
Tiger (Original Release = 4/29/05, .1 Release = 5/16/05 -> 17 days)
Panther (Original Release = 10/24/03, .1 Release = 11/10/03 -> 17 days)
Jaguar (Original Release = 8/24/02, .1 Release = 9/18/02 -> 25 days)
Puma (Original Release = 9/25/01, .1 Release = 11/12/01 -> 48 days)
Cheetah (Original Release = 3/24/01, .1 Release = 4/14/01 -> 21 days)
You can be sure that Apple is already working on the 10.7.1 update as we speak, it'll be out right around the corner. Apple has a busy couple of months coming up here; with new Mac hardware on the verge, and rumored new iPhones in the next 60 or so days, they have every motivation to make Lion's release "final" and begin the normal maintenance life-cycle.
If Apple does not come out with a new GM today or tomorrow, I'd be SHOCKED if what is currently the GM is NOT the final retail 10.7.0 release.