Facebook's app for iPhone and iPad tend to get a bad rap, but two anonymous engineers close to the source say that a completely rebuilt version is on the way with a heavy emphasis on speed. The current Facebook app for iOS is written with a lot of HTML5, but the updated one will be made with Objective-C and be released for iPhone later this summer. There's no mention of a timeline for iPad, but hopefully we'll see it at the same time.
Aside from improved performance, however, we likely won't be seeing any new features or user interface. The last update included Pages Manager, photo support in Messenger, and for a brief period the ability to find your friends via GPS. On the developer side, Facebook has recently enabled developers to include Like buttons in their apps.
Facebook and Apple have been pretty cozy lately, having partnered up for deep integration in iOS 6. Who knows exactly how far that partnership extends, but it's easy to imagine Facebook getting some pressure to update their app after sealing the iOS 6 deal. Soon Facebook will have a bit more competition on iPad when Google+ gets released, but until then, Facebook has a chance to get everything up-to-date.
How unhappy are you with the speed of the current Facebook app? Is it entirely unbearable? Did Facebook really have to rewrite the whole thing?