India have traditionally done well against NZ outside of NZ and on most ocassions beaten them comprehensively . Remember the WC 2003 match . NZ 149 all out .
The second most important thing is that the current Indian side is very different from the sides of the past . Indian batting sides of the past were good on slow wickets of the subcontinent and were a very strong batting side in the subcontinent but the current crop of players except for Dravid and Tendulkar are not so good on the sluggish wickets like SRL . Yuvraj , Ganguly, VVS Laxman and most importantly Sehwag are all at their dangerous best when the ball comes on to the bat though they would struggle a bit if it moves around ( it does not bother Sehwag anyway) . Expect India to be a far better team than what they looked in the IndianOil Cup . In fact , it has not been that bad a start . I agree that they lost 3 games to SRL but those were close matches and India were on top at some stage . Also , even in the best of form , India have not done well in Srilanka over the years . Eventhough Srilanka have been a better side in Sri Lanka , they have rarely managed to beat India outside of Sri Lanka. India have a 100 % success rate against Sri Lanka outside Srilanka in the last 5 years .
India V Sri Lanka , Taunton 1999 --------> India won
India V Srilanka , The Oval 2002 --------> India Won
India V SRL , Birmingham 2002 ------> India Won
India V SRL , BVristol 2002 ----------> India Won
India V SRL , Johannesburg 2003 -------> India Won
On all these ocassions India have done well only because they are a better side on the true batting tracks in England and SA and Sri Lanka are not half as potent on the tracks which are not helpful to spin (although they have Vaas)
I feel India can beat NZ but it will be close .
In the past 2 years we have won matches in England , Australia , Pakistan , West Indies but not a test series or ODI series in India (We home drew test series Vs Pak,NZ , beat SA , lost to Aus ) It proves that India are no longer the side they used to be on the slow tracks .