Gone are PICT resources in the resource fork, here to stay are packages. Packages offer an extreme amount of flexibility. For example, applications can include support for multiple languages. Wham, bam, merci beaucoup mademoiselle. Something for Everybody Packages are not something that will simply benefit the power users, the new users, or that weird guy that sometimes sits next to you in the office cafeteria.
Packages offer a wide range of benefits to a wide range of people.
Basically, packages offer the chance to get back to those old days, when relative newbies could give their friend a nifty little application and not worry about whether it had all of its libraries and extensions and so forth. Packages will make Mac computing easier. But hey, that's not all that power users will gain. This .plist is just one piece of the Network Time package, and it can easily be altered. Even if Apple pulls PropertyListEditor from a the Mac OS X that will ship in summer, a simple text editor is all that's needed to edit these XML files.