It's probably overdue! A lot of the security issues we all complain 
about in Windows is due to holes left over from the earlier days of 
Windows when there was no consideration for networking, etc.

I would say that one of the reasons MS has always tried to maintain a 
high degree of backwards compatibility is to prevent people from 
switching to alternative OS's. My guess is that they bought VirtualPC 
was to get some expertise in virtualization - I believe that when they 
decide to discontinue support for DOS, 16 bit, and 32 bit apps in a 
future version of 64 bit Windows, they'll include (or maybe sell) a way 
to run older apps in a virtual machine rather than support them directly 
in 64 bit Windows.

Of course, this'll provide up a big chance for other OS's that let you 
run older Windows and DOS apps under virtualization - a great 
opportunity for Linux with some virtualization software (or Wine and 
DOSEMU) as well as Macs with Parallels or VMWare.

Anders Jonsson wrote:
>  Why would Microsoft drop all
> support for 16-bit programs or/and DOS programs in Vista? What would they 
> gain by removing that possibility? Wouldn't that just affect the sales 
> figures? If you can't runt your old programs you might not upgrade.
> 
> Anders
>