The proposal would allow users to easily select their preferred software to install from the original system installation instead of making them do so afterwards. More importantly, providing the interfaces for tighter integration would let users choose from a wider selection of options, including those that are not pre-installable. This would not be much different from the distributors of most other operating systems--somebody who installs SuSE Linux chooses from several web browsers that integrate just as well into a unified desktop environment (and, admittedly, many more that don't try and integrate themselves to the same extent).
This is much different that the criticisms being put forward, such as: "The idea of having a ballot screen as a whole is a ridiculous idea. The entire purpose of this ballot screen would be to promote competing products within Windows. Hello!!! Do I really need to explain to you how ridiculous that is? You can't honestly look me in the eyes monitor and not laugh a little inside at the thought of this. To use some of my wacky (and somewhat amusing!) analogies again, that's like Pepsi putting a label on their drinks saying "Have you tried Coke lately?" or General Motors hanging a little air freshener in all of their cars with the message "Perhaps you would prefer a Toyota?" Come on, it's crazy!"
This is instead much closer to the situation of choosing between the Toyota ZZ engine that comes stock, or a Chrystler Hemi if the user wants to feel more power, or a Honda L engine if the user would rather bias the design towards efficiency. Although not all car manufacturers will let you choose an arbitrary engine to fit your taste, most provide some degree of flexibility: Subaru lets me choose an Impreza from 160hp to 300hp, Volkswagen lets me choose between diesel and petro fuel in their Golf and has announced a hybrid engine option.
The problem is that MicroSoft doesn't offer any real options. While they offer several varieties of the same software distribution, this is just one software package that has been crippled in increasingly severe ways to create lower value variations. One way around this is to force MicroSoft to license their software to third-party distributors who would choose what software to build a distribution around.