It certainly moves us forward, but I'm not sure I like the direction.

With the traditional (paper ballot) voting there are several principles that are key to the legitimacy of the election process:

1) The paper ballot could be verified by any citizen and doesn't require any specific knowledge. Any voter could be sure that his vote is accounted for correctly. The ballots could be counted and re-counted without any technical obstacles and alterations. Various NGOs, organizations and individuals could act as guardians of the fair and independent process. This is very important as it provides trust in the process by making it more open. It's technically impossible to make the electronic process easily verifiable and tamper-proof. Any verification will require specialized knowledge, automatically barring a majority of the citizens from any verification. In most democratic elections the process is open to participation by the members of the general public as either observers (controllers) or counters.

And I'm not even talking about gaping security problems that have been discovered in the past with eg. Diebold's e-voting machines [1][2][3] - I never quite understood how the citizens of USA and the government could accept such a thing in the first place as this undermines the whole election process.

2) The paper ballot leaves a trail that is easy to verify and rather difficult to falsify on a large scale without leaving a ton of traces. This process has been refined and improved for a long time and is quite durable if followed properly. Electronic voting (either remote or using e-voting machines) on the other hand provides lots of opportunities for errors and fraud - software bugs, accidental or deliberate software modifications, poor UX choices, etc. The incentives and the payout of fraud are simply too big.

3) It provides decent protection against double-voting. Double voting with paper ballot is still possible, but is so hard to implement on a scale of any significance, that it's almost pointless.

4) Paper ballot guarantees the secrecy of the voting. This might not seem very important for countries like USA where oppressive regimes are not the norm, but is crucial for other places where vote bullying or outright buying are rampant. Even if I was in USA I'd prefer to keep my political preferences and whom I vote for to myself. I wouldn't want elected officials to use my competitor's services only because the CEO enticed his employees to vote for a particular candidate (yes, I do realize that lobbying and political campaign financing are closely tied in USA, but that's tangential).

The Germans have considered electronic voting in 2009 and their Constitutional Court has declared electronic voting as non-constitutional. The motives, in English, could be found on the court's press pages [4].

The technical details of the Estonian system in English could be found on their site [5].

[1] http://www.salon.com/2011/09/27/votinghack/

[2] http://www.securityfocus.com/news/11391

[3] http://www.blackboxvoting.org/presskit.html#hack (terrible design, but has a lot of info)

[4] http://www.bundesverfassungsgericht.de/en/press/bvg09-019en....

[5] http://www.vvk.ee/public/dok/Yldkirjeldus-eng.pdf