According to some screenshots BGR received from an Apple source, it looks like might just be testing those currently iOS 4.3 for iPad-only multitouch navigation gestures on special internal iPhones as well.
Now the part about 4 or 5 fingers makes sense on iPad but on the much smaller iPhone screen it... seems a little cramped. BGR thinks their previous no-Home-button iPhone rumor could lead to a Palm Pre-style gesture area instead. Engadget, which believes the screenshots could be genuine, thinks iPhone 4 could have a bigger screen or it could just be placeholder text from iPad and less fingers will be required if it goes primetime.
Then tell us if you want it?