In spring 2010 norwegian also seems to
be active on the route six days a week (not on Saturday it seems). They
offer very low prices, and use a Boeing 737-800 on the route in March
2010.
With norwegian the total return fare including taxes is often as low as around 64 euro.
In March 2010 their flight seems to leave Amsterdam at 5:10 pm, but in april it seems to leave Amsterdam at 9:25 pm.
Norwegian also seems to be active 6 days a week on the route
Amsterdam-Copenhagen.