IE 7's new streamlined look resembles Vista's. The back, forward, and favorites buttons, and the address bar, are all compressed into two rows up top, along with a new search box you can customize with your choice of search engine. You won't see a menu row with standard XP options like File, Edit, or View (you can bring it back if you want). But you will see welcome new tabs--which you can drag and drop to arrange as you wish--for viewing multiple pages within one IE window.
You also get a new session-saver option: When you close the browser, you can click a box to have IE remember your open tabs, then open the same ones next time. This small but highly useful feature could gradually make a big difference in your daily browsing.
The tabs don't get their own row, however, so they can start to appear somewhat squished if you have many open at once. To navigate, you can click a small button that shows thumbnail previews of all your open tabs on a new, temporary page, and then click one of the thumbnails to activate its tab. You can also select from all open tabs via a drop-down list accessed via a small button to the left of the tabs.
While less obvious, Firefox 2's tab updates are generally a step ahead of IE's. For example, you can configure Firefox to always save your last session for future use; with IE 7 you have to click a box every time. Firefox also lets you reopen closed tabs via the History menu or by right-clicking an open tab.
As in IE's implementation, each Firefox tab has its own closing button. However, Firefox provides no thumbnail previews of open tabs.