From CNET (Feb 10, 2006):
Opera has released to the public Opera 9 Technology Preview 2, a first look at the features and tools slated for the next release of this popular Internet browser. That said, this is still a technical beta, designed more for Web sites to make adjustments and for technical users to make comments. As for Opera 8, Opera is no longer a for-pay browser, joining Firefox and Netscape as free alternatives to Internet Explorer. Opera 9 Technology Preview 2 offers two big additions, plus several that put it in league with Firefox 1.5 and Internet Explorer 7 for XP SP2 Beta 2.
BitTorrent support: Opera 9 will be the first mainstream browser to support streaming BitTorrent media. Opera has optimized the browser so that you no longer have to mess with setting the port or tinkering with the upload and download speeds. BitTorrent is currently very popular in Europe, but with its inclusion in Opera, that could spread worldwide.
Widgets: Opera 9 will embrace Ajax technology by offering tiny applets with specific functionality, such as converting currency. There's even a widget that displays the latest Slashdot posting on your browser screen.
Customized search engines: Like Firefox and Internet Explorer 7 for XP SP2 Beta 2, Opera 9 will allow you to choose your favorite search engine with ease.
Improved pop-up blocker: Like Firefox and Internet Explorer, Opera has always had the ability to stop pop-ups, but advertisers have gotten more creative. This new pop-up blocker within Opera 9 should keep almost all the distracting, flashing, and noisy messages from interfering with your enjoyment of the Web.
Site specific controls: Say you trust one page and not another. Now you can toggle your security settings to match specific pages within Opera 9. Think of it as security zones within Internet Explorer--but better.
Thumbnail images: Firefox already gives you the opportunity to mouse over any open tab and see a thumbnail of that page. Internet Explorer 7 won't, but will offer a single page displaying thumbnails of all open tabs. Opera opts for the former, allowing you to mouse over a tab to see a thumbnail of the content within. Of the two choices, we prefer the mouse-over method best.