In this blog, Microsoft state that what they are seeing 'the phenomenon' as the correct implementation and Win 7 is performing as designed... Which means if you are seeing this error message from your notebook, that your battery is indeed reaching the end of its service life...
http://blogs.msdn.com/e7/archive/2010/02/08/windows-7-battery-notification-messages.aspx
Some data points from the art
...
Windows 7 laptops/netbook/notebook users are experiencing an issues where the users may receive a message “Consider replacing your battery” even if their system or battery is new and there was no issues with it before.
This is not impacting all Windows 7 laptops. Some of the laptops/netbooks/notebooks impacted that we know off are:
Asus Eee PC 900
Asus Eee PC 701
LG Xnote R500
HP DV60
...