I am reading a little bit on Objective-C, and since it comes from Smalltalk, like Ruby does, so I wonder, is it true that if using Ruby, (if Apple change XCode to support it), to develop iPhone or Mac app, it is not suitable really because of the speed?   For example, Angry Birds probably isn't as smooth as it is now if using Ruby, vs if Objective-C, it is compiled and running as machine code.
But currently, is there any way of compiling Ruby or Python code into machine code so that it is running in the similar speed zone as Objective-C programs can?
Python and Ruby themselves are not too fast, but many programs today are written to basically do none of the heavy lifting alone. For instance, if you want to save a PNG file as a JPG, you are certainly going to use the built in system calls to do it. In that case it does not really matter if it takes 0.00001 seconds in Obj-C, or 0.001 seconds in Python to process the mouse click, when the optimized system code to convert the image is the exact same code in both programs, and takes, say 1/2 a second to run. On the other hand if you are making a low level data munger of your own design, then you might want some C. Basically all languages that you would use on a Mac allow you to write something in C, and call it from that language, so even that does not slow you down. 
Pick the language for the task based usually on what everyone else is doing for that problem, intersected with your abilities.
Is Ruby or Python not suitable for iPhone or Mac app development because of speed, and any compiler that can help boost the speed?