Microsoft's IE blog says: "To help our customers become more secure and up-to-date, we will distribute IE7 as a high-priority update via Automatic Updates (AU) shortly after the final version is released for Windows XP, planned for the fourth quarter of this year."
Also:
If you decide to install IE7, it will preserve your current toolbars, home page, search settings, and favorites and installing will not change your choice of default browser. You will also be able to roll back to IE6 at any point by using Add/Remove Programs in the Control Panel. Finally, users who have AU turned off will not be notified.
Corporate users will be able to block the download, but Microsoft wants it widely installed for security reasons.
Comment: Since Microsoft has made IE part of the operating system then it makes sense to distribute it via Windows Update. But since IE7 is still a long way off, I'd recommend IE users upgrade to Maxthon. This is based on IE so it renders Web sites the same way, but it offers tabbed browsing, mouse gestures, RSS reading and other features still missing from IE6. (I'm assuming that, by this time, you've already got or at least tried Firefox.)