In-game models have certainly moved on substantially since the original GoldenEye was released in 1997. Back then, an AK-47 was little more than a few black polygons with a pointy bit at one end. These days, each weapon is paintstakingly rendered by the team's nine 3D Artists, and then brought to life by a further six 2D Artists with high-resolution textures.
Here you can see the startling Before / After shots of the nude 3D model versus the final rendered model complete with textured skin. The work doesn't stop there: each gun then needs to be animated for recoil, bullet casings flying from the chamber etc while melee weapons like the Knife clearly need a greater range of motion.
Here are more of these amazing models, yet to be skinned / textured:
The final arsenal will include the famous Walther PPK 7.65mm pistol, P90 assault rifle, various mines and even Throwing Knives. The Moonraker Laser sounds like fun too.
GoldenEye: Source will be a freely available download requiring only a copy of Half Life 2. The team are yet to announce a release date, and while their original estimate of Summer 2005 has lapsed, everyone involved is working very hard to get it completed as soon as possible. If you are interested in lending a hand, visit their Recuitment page