Tiger's reference to 1 major a year was not to be taken into this exact context. When he says winning 1 major a year is a good year he is saying that majors are more important than other tournaments. That yes it is good to win 7 or 8 tournaments in a given season but it isn't a great year until you win a major. Thus if he wins only 1 or 2 other tournaments in a somewhat down season, if he wins a major then it is a great year.
Yes he did go for a stretch without winning a major....to be exact it was 2nd half of 02 to masters victory in 05...10 tournaments without a win. However that was during his period of changing his swing and since that victory in the masters in 05 he has won 5 majors in 12 tries (3 year period) and finished 2nd twice. More than 1/year...**** nearly 2/year.
He is playing even better golf than that now so I don't see it unthinkable that he could improve on that 5 major wins in the last 3 years and possibly make it 6-7 major wins in the next 3 years. I predict the 6-7 majors in the upcoming 3 years vs. a Grand Slam this year.