Its true, but its a long way off.  The next version of Exchange (referred to
as E12) will have public folders depreciated and then removed in the version
after E12.  The term depreciated in this case means that the feature is
optional (doesn't install by default) and Microsoft wants to see folks move
to another solution for collaboration (e.g. SharePoint).

They will be around and can be used for at least ten years.
There are no good alternatives currently for everything you can do with
Public Folders and there is a vast amount of knowledge and tools available
for them.
imho it's all about money.
The MS strategy is to move everybody to their future internet based ASP
model and you will be paying per click or cpu cycle. They need to move
everybody to web based services now in order to make future migration
possible.
It's the only possible future for MS. I mean how many new features can they
continue to come up with that people really need and buy a new license for?
Already loads of people still use Office 2000 and don't upgrade.