Will this have any effect in practice or will it just be the same as the different trust levels in .NET? The functionality for sandboxing is built in it's just that nobody uses it or knows how to test or enforce it. (with the exception of sysadmins).
In any case i welcome all sandboxing, this is even something i would consider switching from windows because of, given that it actually works out good. Let's take an example from yesterday, i want a simple pdf-merge program. As it is now i have to spend 20 minutes researching a program on forums and other sites before i even install it to see if it's safe and everything. Compared to just installing and see if the result works. This is also why web apps are so popular, you can try hundreds of them with 0 risk for your other data.
In any case i welcome all sandboxing, this is even something i would consider switching from windows because of, given that it actually works out good. Let's take an example from yesterday, i want a simple pdf-merge program. As it is now i have to spend 20 minutes researching a program on forums and other sites before i even install it to see if it's safe and everything. Compared to just installing and see if the result works. This is also why web apps are so popular, you can try hundreds of them with 0 risk for your other data.