After the web learned earlier this week that the final name of Vista's successor was Windows 7, all hell broke loose. The general consensus was that Windows 7 wasn't a bad name, but the reasoning behind it wasn't very clear. Many couldn't figure out how Microsoft had reached the number 7 (I'll give you a hint: they were looking at the kernel version number, instead of counting every single minor and major Windows release). But then others wanted to know why the current builds of Windows 7 were at kernel version 6.1, not 7.0.
Mike Nash, Corporate VP of Windows Product Management, chimed in again on the Windows Vista Team Blog with the official explanation:
"So we decided to ship the Windows 7 code as Windows 6.1 - which is what you will see in the actual version of the product in cmd.exe or computer properties. There's been some fodder about whether using 6.1 in the code is an indicator of the relevance of Windows 7. It is not. Windows 7 is a significant and evolutionary advancement of the client operating system. It is in every way a major effort in design, engineering, and innovation. The only thing to read into the code versioning is that we are absolutely committed to making sure application compatibility is optimized for our customers."