According to CNN/Money,

"Consumers can expect retail gas prices to rise to $4 a gallon soon but whether they stay there depends on the long-term damage to oil facilities from Hurricane Katrina, oil and gas analysts said Wednesday.

'There's no question gas will hit $4 a gallon,' Ben Brockwell, director of pricing at the Oil Price Information Service, said. 'The question is how high will it go and how long will it last?'

OPIS tracks wholesale and retail oil prices and provides pricing information for AAA's daily reports on fuel prices.

Brockwell said with gasoline prices now exceeding $3 a gallon before even reaching the wholesale level, it 'doesn't take a genius' to expect retail prices to hit $4 a gallon soon.

'Consumers haven't seen the worst of it yet,' Brockwell said.

Katrina forced operators to close more than a tenth of the country's refining capacity and a quarter of its oil production, which sent gasoline prices surging."

At least we'd still be paying a whole lot less than Amsterdam. Towards the end of the article, some other guy's research suggests the prices would level off around $3.50, then eventually go back down.