They said that the update is done in-place and apparently without a reboot.

> Adobe Acrobat, Skype updates and the like.

More often than not the installers and updaters decide unilaterally that a reboot is required and force the user to perform one when it's not needed.

The unix style of file locking sure is showing it's advantage over Windows. Not that rebooting for an OS upgrade is too onerous, but using Windows one has to reboot for the most trivial things - Adobe Acrobat, Skype updates and the like.

This has been said many times before but on OSX you actually need to reboot after updating Safari. I'm not 100% sure about iTunes but I believe it still needs a reboot after updating.

Hopefully that will get fixed. Generally the reason why the reboot is required is because WebKit gets updated and that is a library that is loaded into various different applications the best way to restart all of them is to reboot, with the new state keeping that Lion is doing that will become simpler.

I got a 4mb font update a couple weeks ago that required a reboot. My dusty PC was looking good to me that day.

Potentially this uses more space that a "true" overwrite.

It is in-place with a reboot.