Firefox 3.6 boosts speed by about 12 percent over Firefox 3.5, which is fine, but not exceptional. Its new Personas feature lets you skin the browser by changing its colors and adding graphics. The browser will notify you when add-ins are outdated, which is useful, because outdated add-ins are security holes.
Add it all up, and it's not earth-shaking. These are relatively small incremental improvements. There's nothing wrong with the upgrade, and Firefox still remains my browser of choice. But it's far from an exciting release.
Firefox isn't at fault here. The problem is that by now browsers are so packed with features, that all the important capabilities are already in place. Software has a natural life cycle. In the early days of a type of software such as word processors or spreadsheets, developers rush to add new features. After a while, though, there's simply not much to add. When was the last time a great new feature was introduced for a word processor, for example? For a spreadsheet?
It may be that we've reached the limit with browsers as well. What's there needs to be fine-tuned --- more speed, better security, niftier add-ins, better tab handling, improved Favorites management. But I can't think of many new killer features I'd like to see added.
How about you? What nifty new features would you like to see in a browser? Do you think the time of browser innovation is long past?