There have recently been some rumblings (e.g. this article at the Christian Science Monitor) of a group called Noah's Ark Ministries International claiming to have discovered what they believe to be Noah's Ark.
Short response: They didn't discover Noah's Ark.
For a longer response, I'm going to cite Robert Cargill's excellent article Forget About Noah's Ark; There Was No Worldwide Flood.1
Cargill does a very good job pulling together most of the main scholarly and scientific arguments against the historicity of the Flood and the Ark - the clear influences of earlier myths on the story, the mutually exclusive details within the composite story in Genesis, and the utter impossibility of there being enough water in, under, and over the Earth to cause a worldwide flood.2
In reference to the influence of older Mesopotamian flood myths, Cargill writes:
These flood stories appear to have been transmitted to the Israelites early in Israel’s history. Contact between the Assyrians and the Israelites is known from the conquest of Israel and its capital, Samaria, in 721 BCE by Assyrian King Shalmaneser V (727-722 BCE), and from the attempted conquest of Jerusalem by the Assyrian King Sennacherib (704-681 BCE). These stories were apparently modified to conform to a monotheistic faith, but retained characteristics such as the destruction of nearly all living things via a flood, the salvation of a select few people and animals by the construction of a boat, and the regret of the deity for the flood, prompting a promise not to do so again. Thus, like many of the early stories in Israel’s primordial history, the flood story appears to be an adaptation and integration of a previously known myth into the theology of Israel.
This might lead some to assert that the similarities count as evidence that the underlying story is true (although I rather doubt that those asserting this would claim that the Epic of Gilgamesh and the experiences of Utnapishtim represent the ground truth of the tale). I think rather that the similarities count as evidence that people tend to settle near water, bodies of water experience flooding occasionally, people share experiences and stories across cultures, and cultures are often syncretic.
It would be a bit surprising if early Israel didn't have a flood myth.
Anyhow, one of the points Cargill makes - that the notion that if part of the Bible is demonstrably untrue, then all of the Bible is consequently untrue is simply incorrect - cuts to the heart of the issue. Let's re-cast the statement: The book Dracula talks about vampires, England, Eastern Europe, nuns, rivers, sailing ships, wolves, and elements of the history of Romania. The fact that vampires are fictional doesn't mean that England, Eastern Europe, nuns, and so forth are also fictional. It does mean that if you read Dracula, you have to be somewhat more discriminating about what is actual history in the book and what isn't. Nobody is getting uptight about people not taking Dracula literally, but lots of people get very vocal and emotional when myths like the Genesis flood are called into question.3
What is interesting to me is that if you step away from the modern apologetics that have grown up around the flood myth, and look at it through an ancient Mesopotamian cosmology, the story makes sense. A view of the world then basically had the surface of the Earth as a flat expanse of land with water at least partially surrounding it, and a bowl-shaped sky that kept water above it from falling on the Earth. With that sort of model of the world, things like fountains of the deep and floods of world-wide extent aren't so absurd. You don't have the nagging little issue of Noah having to somehow get animals from (for example) the Americas and Australia to his Ark.4
Then, once you've stopped worrying about trying to reconcile the myth with history, you can start thinking about what the myth is really trying to express.
1Cargill has another article, here, addressing the most recent claims specifically. Definitely worth the read, but overall more detailed than I want to get into here. I first saw a link to the article that I'm directly referencing over at Exploring Our Matrix, where James excerpted it as a quote of the day.
2Cargill leaves out any discussion of the fossil record, I suspect because using the fossil record to refute the Genesis flood is rather like using a tactical nuke to get rid of a squirrel in the attic. That doesn't stop some folks from claiming that the fossil record supports the Genesis flood, but they inevitably misunderstand the data. I'll simply mention marsupials and leave it at that.
3I am not insensitive to the fact that the story of Noah is very important to a lot of folks. That's fine, but I think it's a problem when people reject huge amounts of scientific evidence refuting the story on the strength of the fact that the story is in the Bible. The Bible shouldn't get any special consideration just because it's the Bible - if anything, it should be picked apart character by character and subjected to extremely minute criticism. If it's as important as people want to claim, it should be able to stand up to the scrutiny.
4Again with the marsupials.