Updated: Mike Nash, corporate vice president of Windows Product Management, explained:

"Over the years, we have taken different approaches to naming Windows. We've used version numbers like Windows 3.11, or dates like Windows 98, or "aspirational" monikers like Windows XP or Windows Vista. And since we do not ship new versions of Windows every year, using a date did not make sense. Likewise, coming up with an all-new "aspirational" name does not do justice to what we are trying to achieve, which is to stay firmly rooted in our aspirations for Windows Vista, while evolving and refining the substantial investments in platform technology in Windows Vista into the next generation of Windows."

Ultimately, Windows 7 is the seventh release of the operating system, "so therefore 'Windows 7' just makes sense," Nash writes.

Microsoft has set early 2010 as its release target for Windows 7. The company plans to reveal much more detail about the software at its Professional Developers Conference at the end of the month.

Ed Bott had a great post earlier this month on the branding of past versions of Windows, including a reader survey in which only 15 percent of the 2,800 people who responded expected Windows 7 to be the final name.

What do you think of the name Windows 7?

Update, 4:18 p.m.: Jerry asks in the comments how this can qualify as the seventh release of Windows. He counts this way: Vista, XP, 2000, 98, NT 4.x, 95, 3.x, 2.x. 1.x.

A couple of commenters offer these answers: david writes, "because version 1.x and 2.x were not truly windows but DOS :) - Only from 3.x, they had GUI and the ability to 'multi-tasking.'"

The folks over at the AeroXperience blog are also wondering about this, and they've drawn up version lists for both business and consumer-targeted iterations of Windows.

Getting a bit more technical, they've counted the kernel releases:

1. Windows

2. Windows 2
3. Windows 3
4. Windows NT (NT 4)
5. Windows 2000 (NT 5)
6. Windows XP (NT 5.1)
7. Windows Vista (NT 6)

"That's 7 releases right there, including XP. If XP isn't counted because it's Kernel 5.1 (which would bring the total with Windows 7 back down to seven), then why is Windows 7 being counted as the 'seventh' release if it's kernel 6.1? I hope I'm not the only one seeing the naming problem here.

"Kernel increments are used mostly for application compatibility purposes, but still, the logic is lost upon us as most people would count XP as a semi-major release in comparison to 2000."

I've sent a request for clarification to Microsoft and will update this post if I learn anything.

Update, Tuesday, 3:21 p.m.: Microsoft has issued an explanation on how they counted previous Windows releases to get to seven. Check out the details here.