Through Ethereum this creates a transparent voting system where anyone can audit a poll, since everything is recorded in the Blockchain. Additionally, votes cannot be altered once they are cast, ensuring the integrity of the system.

Right now this is a Proof of Concept though, more voting applications will follow.

But what's to stop vote tampering between the webpage and the blockchain? Couldn't you easily make up false votes or record votes wrongly?

The website is currently a single Point of Failure, since it is the gatekeeper for recording votes into the Blockchain. With this proof of concept I did not want to build a fully decentralized voting application that ensures that 1 person == 1 vote, I rather just wanted to display how Ethereum and the Blockchain can be utilized for voting. Once a vote is recorded into the Blockchain it cannot be altered anymore. The question of feasibility of this application is obviously very much up in the air.

But overall, there are some interesting concepts to protect such systems against sybil-attacks, so that we can ensure that 1 person == 1 vote any nothing more.

You just run your Ethereum client on your machine and use it to verify the data on the blockchain.

Decentralization my friend. Vote tampering is a huge problem with current systems and this is aiming to mitigate that by using a public blockchain