And to complete this, even if you compare W7P with the early iPhone OS (arguing that both are version ones, not that they're both living in 2011), the first 6 months Apple shipped 1 major updates, 3 bugfix updates and 1 compatibility update (for the 1st gen iPod Touch).

And a second major update in month 7.

2.0, 3.0 and 4.0 were all followed by 2 major and 2 bugfix updates in the first 6 months.