The government has chosen to appeal the decision, and the case will go to the Supreme Court in December, although there is little reason to expect a different result.
Some people are thinking that this may lead to an effort to block Brexit, but this is unlikely. Many pro-remain MPs have already said that they will vote to invoke A50, as the government should implement the decision the public made in the referendum. The outcry at this result should be enough to show MPs that blocking Brexit is a dangerous path to go down. What this does mean however, is that MPs can seek guarantees from government on the exit strategy before allowing the process to continue, meaning that the government may now be forced to reveal its negotiating strategy to much greater extent that it had intended. Jeremy Corbyn initially suggested that Labour could hold the process up unless guaranteed access to the single market, which is a nice try despite that terminology being completely meaningless. Days later, Tom Watson said that Labour would not stand in the way and Corbyn retreated and confirmed this. I suspect the Lib Dems will do their best to step into the functioning opposition void and keep things interesting.
Of course, Nigel Farage had to do the rounds suggesting that we are on the verge of a "great betrayal". Farage seems to think that a vote to leave the EU was also a vote to leave the single market, which it fundamentally was not. A small but vocal part of the leave voter base, and even some within the various Leave campaigns voted specifically with continued single market membership in mind, at least as a transitional arrangement.
Either way, and in spite of the media narrative, every signal the government has given us thus far indicates that they fully intend to maintain full membership or at least preferential access to the single market through something similar to the EEA agreement, because that is basically the only way that Brexit can be done in two years; so in reality, this ruling may affect the timescale but is unlikely to affect the outcome.
Jolyon Maugham breaks down the implications of the ruling for Prospect Magazine , indicating that A50 by March 2017 is very unlikely. Opinions on the ruling vary significantly, as shown by this host of commentators giving their opinion in the Guardian.
Ian Dunt argues for Politics.co.uk that for one sweet moment, Britain is sober again. Jamie Foster is much less pleased over on his blog, but sees the ruling as no more than a temporary setback. The pro-leave Spectator also chipped in, calling for Brexiteers to accept that Brexit means protecting UK laws and courts.
Research organisation The UK in a changing Europe released a report last week looking at the process and some of the options lying ahead of us. The report offers some timely new insights whilst retreading some old ground, but is a worthwhile read for people trying to keep up with the process.
Duncan Weldon writes for the Guardian that anybody expecting a single market deal that includes limits to free movement are going to be disappointed. Former Canadian PM Stephen Harper offers advice to the UK on doing trade deals in the Telegraph, making it obvious that something like CETA cannot be done in just two years. Vincenzo Scarpetta writes for OpenEurope that WTO provisions provide a good framework for transitional arrangements between the UK and the EU-27, and require that all bridges lead to something better.
Finally, Sam Bowman of the Adam Smith Institute looks at the rash reactions to the falling pound from both sides of the Brexit debate in the IB Times, and argues that with the right politics, we can overcome the shock of Brexit.