With the release of its latest Web browser possibly just weeks away, Microsoft is concerned that some of the Internet's busiest Web sites won't display properly in the new browser because of compatibility issues.

The problem: Internet Explorer 8 adds support for Web standards long ignored by Microsoft. "Some of today's Web pages might expect the old, less interoperable behavior from IE," wrote Microsoft Explorer program manager Scott Dickens, in a blog post Wednesday.

"These Web pages might not function correctly, in ways from just looking a bit misaligned to not working at all," wrote Dickens.

While standards support is generally viewed positively in the software industry, most Web developers design sites with Explorer in mind because of its overwhelming market share. Pages built for Explorer 7 or previous versions of the browser might not support the standards that will be built into IE8.

With Explorer 8, Microsoft has promised default support for W3C Internet programming guidelines. Among other things, IE8 will feature default compatibility with Web standards such as CCS 2.1 and HTML 5. It also promises improved support for the Ajax language.

Microsoft testing has revealed that CNN.com, Facebook, MySpace and BBC.co.uk are among the sites that, in their current configuration, won't display properly in IE8. "Despite all the outreach to sites, we saw from telemetry data that that IE8 Beta 2 users still have to use Compatibility View a lot," wrote Dickens.

Compatibility View is a tool that IE8 users can employ to view pages designed for IE7. Dickens said Microsoft will add a feature to IE8 that displays a list of sites that should be accessed through Compatibility View.

Though speculation had pegged IE 8's release for sometime in the current year, a Microsoft executive has confirmed that the browser won't ship until early 2009.

In a blog post, IE general manager Dean Hachamovitch said Explorer 8 won't be released in final form at least until the first quarter of next year. In fact, the browser will be undergoing beta testing into the new year, said Hachamovitch.