Well, christianity did eventually take hold of the Vikings and became the norm. You either embraced Jesus or your head took a permanent leave of absence, unless you escaped to Iceland, and many did. Still, I wouldn't say christian beliefs exclude you from being a viking (They're not my beliefs, just to clarify), though the faith does tend to frown upon pillaging and taking liberties with local nuns.
Actually you raise an interesting point, once christianity became the norm, did the Norwegian people stop being vikings? Is raiding and pillaging even a prerequisite to hold that title? This thread gets more and more interesting with almost every post.
Christianity didn't really become the 'norm' until around 1050-1100. Up until then most of the vikings (Danes at least) became Christian due to the intense missionary work of primarily German and French monks who erected churches throughout the country (Denmark). The way they persuaded the vikings to convert to Christianity was by bribe. 5 cows went a long way, and a viking didn't think he'd insult the Nordic gods by adding another God to the list. After all, they were nice cows, of which at least one could be sacrificed to Odin as to calm him down, should he frown upon the new God. The vikings were merchants, and cunning ones too. The bribes offered by the Christian church didn't convert them as such, they just agreed to also worship the new God. After all, he was a merciful God, unlike the old ones. You could still pillage and plunder and just ask for forgiveness afterwards. You didn't even have to sacrifice your livestock to him, just one day a week in church, maybe only once a month, depending on which deal you had struck with the monks.
The old gods and rituals were still in use at least a century after Denmark officially became Christian (Harald the Bluetooth was the first viking king to be Christened and declare Denmark a Christian nation, but did not force anyone to convert). We still perform some of the old rituals today, like dancing around the May-pole, celebrating the coming of the light, mid-summers eve etc. A lot of it has Christian labels today, though.
So yes, the vikings were very much still vikings even though they were 'officially' Christians. The old ways died slowly over time as no one really did missionary work on their behalf, and the vikings became 'less viking' as the society evolved and provided other means to grow wealth and support the families. (Sadly =)