Update 6/8/09: The release version of Safari 4 went with none of these.
One of my favorite Safari features is that the address bar doubles as a progress bar, whereas most browsers place a progress bar at the bottom of the screen, taking up real estate. This is how mobile Safari works on the iPhone and it is how the current release version of Safari 3 works.
The Safari 4 beta, however, gets rid of this behavior in favor of a little "spinning wheel" that tells you that a page is loading but gives no indication of how much has been loaded. It sits at the far right of the address bar:
It turns out that there are actually three different progress indicators available in the Safari 4 beta. The first is the default choice of the spinning wheel. The second is the old Safari 3 progress bar, which looks like this:
To enable this throwback indicator, load up Terminal and execute these two commands (while these two lines of code are harmless on their own, use caution while messing around in Terminal -- you can easily damage your computer from the command line). To restore the original settings, just replace
defaults write com.apple.Safari DebugSafari4LoadProgressStyle -boolean NO
defaults write com.apple.Safari DebugSafari4IncludeToolbarRedesign -boolean NO
As you might expect, the first line turns the new Safari 4 progress indicator off. The second line restores the entire address bar to its Safari 3 look - meaning the new bookmark button and other embedded controls disappear. You need to revert both parameters to get the old progress bar back.
What happens if you only turn off one setting? That depends on which one you choose. If you disable the LoadProgressStyle parameter but leave IncludeToolbarRedesign on, nothing happens as far as I can tell and the default Safari 4 behavior persists. If you leave LoadProgresStyle on and turn IncludeToolbarRedesign off, however, you get a third, hidden progress indicator:
This little "progress icon" is my personal favorite - it gives complete information with minimal real estate use and distraction. Unfortunately, I like the new address bar in Safari 4 more than I miss a useful progress indicator, so I'm leaving the default settings turned on. Which do you prefer?
p.s. This will not affect your bookmarklets.