One possibility is that programming languages as we know today will be reduced to a minimum.
Back in the early days a lot of work was needed just to display a simple button or edit box, compare that to
today where you use ready made building blocks pretty much all gui elements such as buttons, list boxes and dialogs etc.
Creating an application for registering customers for example could in theory be reduced to dropping a "person object" on
a form. If you need to customize it, adding fields and such could be done without coding.
I think accessing the "code" and modify it would still be possible but most would be written in a simple script language.
More and more programs will most likely run completely independent of platform, compiler output will consist of two parts "appearance descriptor" and "code behind", where it's up to the target platform to render the GUI according to its own standard, and either the platform itself or a remote server will execute the proper code behind, depending on type of application.
This is just a possibility, and seeing as I like the "dirty" code, nothing I'd look forward to, except for the platform independence.
Cheers