Getting contradictory messages about that, hope they're not. I cannot imagine support for it would stop, since a gazillion sites use them.
Some additional questions about that:
In my opinion the W3C jumped the gun in dumping iframes from the Strict HTML and XHTML doctypes. In theory you would use the <object> element to add foreign objects to your document, but browser differences and limitations have made this a nonstarter for many developers. With the much-more-pragmatic HTML 5 (which is still a draft), iframes are back and even have two new attributes: seamless, and the intriguing sandbox.