While Microsoft is still investigating a notebook battery life issue that was supposedly caused by Windows 7, some interesting trends have emerged. First, it doesn't appear that Windows 7 was at fault, and that the machines in question are most likely actually experiencing failing batteries. Secondly, the issue is extremely isolated: Neither Microsoft nor the PC makers that are involved have reported any incidents via official support channels.
In short, this may simply be a non-issue.
Looking at Microsoft's support forums, it's unclear what's really happening. Yes, some people have complained about battery life issues, and some complaints date back to mid-2009, before Windows 7 was released. Some claim that Windows 7 is reporting false battery life information, though Microsoft says in return that the system is working as designed. And some claim that Windows 7 gets worse battery life than Windows XP, contrary to Microsoft's claims that the new OS would get better battery life.
The weirdest complaints suggest that Windows 7 somehow interacts with the PC BIOS in such a way that harms the battery permanently so that future installs, even of different Windows versions, also see decreased battery life. But this scenario is highly unlikely.
In Microsoft's defense, Windows 7 was the most-widely tested OS in history, with over 8 million official pre-release users and, I've been told, an additional 7 million who received the OS through unofficial venues. And Windows 7 is now installed on over 60 million new PCs. The notion that a serious issue of this type could suddenly emerge after installation on such a wide pool of PCs is, while not impossible, certainly unlikely.
Most important, perhaps, is that the battery life issue appears to be extremely limited. This suggests that the customers complaining were on the verge of experiencing actual battery failures anyway. And that the more accurate battery assessment provided by Windows 7 is triggering some user angst, but not any actual hardware issues.
So that's the most likely outcome here. And while I'll stay tuned to see what happens here, I doubt we're looking at a Toyota-style fiasco. If we were, these battery life issues would simply be more widespread