Why don't anyone sue apple for copying their work. It would be nice to patent such tweaks to make Apple pay royalty or something if they want to implement similar functionality.
First, this minor tweak is not going to have much of an impact as few people JB their device for the purpose of call log editing. Most people JB in order to unlock, tether, spoof location, or add a multitude of other features that are not available with the iOS by itself or cost extra money with the iOS.
Second, it is true that the more Apple adds to their iOS, the less JB will be needed.
Third, competition is a wonderful thing. If it were not for the JB community, Droid, and other mobile OS competing with Apple, you will see innovation move a lot slower
Yeah because adding over 200 new features is what they usually do between .1, .2, .3 etc of previous released. Idiot. If this was the case then we would be on iOS 1.14.35
No matter what is added to the official OS, people will still want the ability to customize. If Apple really wants to kill jailbreaking, they'll develop an SDK for tweaks rather than just apps.
I'm not a heavy customizer personally, but, having installed the iOS 5 beta (I'm a developer), I already miss one tweak in particular: SBSettings. It is very convenient to be able to swipe a finger across the status bar to trigger a drop-down of toggles for various common system options: Bluetooth, Wi-Fi, VPN, Brightness, etc.
With this tweak, turning on/off these common options is a swipe and a tap. With the stock OS, it's swiping to the correct home page, tapping Settings, drilling down to the option (which can be 2-3 taps deep) and finally toggling.
Of course, jailbreaking also brings the ability to SIM unlock (if you have the right baseband/modem firmware), to activate Personal Hotspot without subscription to the feature and other "you vs. AT&T" capabilities, but you don't need to go there to understand why some people jailbreak.