There's been no huge reversal in the GBP rate, so the markets seem convinced that article 50 will happen
As has been noted elsewhere: Sterling's exchange rate does not yet seem to fully price in leaving the EU, the costs of which are still unknown. The dollar has been rising against many currencies since the Federal Reserve stopped printing money and lowering interest rates. The pound's move against other currencies is far less pronounced.
The judgement is likely to increase political uncertainty as May may now feel obliged to hold a general election to get a majority in parliament in order to pass a bill on Article 50. At the moment, even if she tabled a motion of confidence, there is a high chance of losing the vote, hence reversing the referendum and then bringing down the government: Gideon Oliver Osborne's hour could yet come, albeit as head of a Tory-Liberal-SNP coalition.
Of course, there is also the possibility of further constitutional shenanigans to try and get round this but I suspect more MPs would vote against the referendum than against the courts.