While changes within Firefox 2 Alpha 2 are bolder and better than those in Alpha 1, they are still best suited only for developers and the technically adventurous.
As seen in Firefox 2 Alpha 1, Places is a new side panel within Firefox 2 that allows you to control your bookmarks, RSS subscriptions, and browser history in one convenient space. The Mozilla team decided recently to disable Places in future releases of Firefox 2, although it--along with the new MozStorage system, which lets you execute a search query of your browser history to find pages you may have visited long ago--will be available to extension authors. Read more here about Mozilla's decision to disable the Places feature.
Although you can currently download an extension for Firefox 1.5 to do this, Firefox 2 Alpha 2 includes Close buttons within the individual tabs, allowing you to quickly remove tabs no longer in use. Another tab-related change within Alpha 2 is the default capability for embedded page links to open new tabs, not new windows. Best new tab feature: automatic restoration of your current tab sessions in the event of a software crash.
Unlike Internet Explorer, Firefox has long had a search box built in to its browser. Now you can quickly reorder your search engine preferences and take advantage of that engine's search suggestion capabilities. Say you want to find information on the White House, just typing white gives you a drop-down menu of recent choices on Google, for example.
Not yet visible on most sites but available within the Alpha 2 code is something called Microsummaries. This allows a page to push out the most important details of that page for display within your browser, such as "weather pages: the current forecast, for example, SF: showers likely." This differs from Really Simple Syndication (RSS) in that there isn't much additional content available, but the content will be updated as often as necessary.
Mozilla also wants to streamline the Really Simple Syndication (RSS) subscription process--currently, you must add RSS feeds as a live bookmark in Firefox 1.5. In Firefox 2 Alpha 2, click a page's RSS icon, and a default RSS reader within Firefox displays the latest headlines from that site (no more ugly XML code).
Now any text that you type to multiline text boxes online will be checked for mistakes. However, only dictionary words are checked, and misspellings are identified with a squiggly red line. Grammar, which includes missing words, will not be checked.
In Alpha 2 you can manage both your extensions and your themes (skins) within Firefox in one console.
According to Mozilla's road map, future builds of Firefox 2 will include some form of antiphishing technology, perhaps the one already created by Google. At present, Google makes an antiphishing extension for Firefox; this extension could become part of the future code for Firefox 2.