I’m not sure what Microsoft is up to. Their latest Windows 7 operating system to be launched commercially by the end of this year comes without a native email client as per cnet news.
Update: I bought a Windows 7 based VAIO laptop a couple of weeks back and it has Windows Live Mail preinstalled.

Most XP users who switched to Vista, found Outlook Express missing but were soon content with Windows Mail, the default email program on that operating system. Users also had an option in Windows Live Mail which could be downloaded and installed for free on both Vista and XP computer. Some have suggested Windows Live Mail for Windows 7 and I would agree with them because I have been using this program on my Vista computer for many months without any problem.

For those who were looking for Outlook Express on Windows 7, sorry, the program is long dead. It’s been (sort of) replaced by Windows Mail in Vista and then later by Windows Live Mail. FYI, Outlook Express development and supported has been stopped by Microsoft.

So if you are looking for an Outlook Express alternative, I recommend Windows Live Mail (free) or Outlook (costing about 100 dollars). Mozilla’s Thunderbird is an excellent Outlook Express substitute if you want to break out of Microsoft’s shackles. IncrediMail and Yahoo’s free email program, Zimbra desktop, will also work on Windows 7 operating system.