Out of curiosity, I just tried uploading a file larger than 100MB to test the limits via the browser and received the following error:
Yowza, that’s a big file. Try again with a file smaller than 25MB.
[1] https://help.github.com/articles/conditions-for-large-files/
[2] https://help.github.com/articles/billing-plans-for-git-large...
I'd have to imagine this is probably the main driving factor. As GitHub tries to make further inroad into Enterprise, I can see them focusing more and more on making things more accessible to non programmers (project managers, secretaries, etc.)
I really won't be surprised if 5 or 6 iterations down the road, you'll have the option to change the repo landing page. For example, instead of showing the files in a repo, you'll just see the README markdown file. And before you know it, they (GitHub) will start marketing GitHub Enterprise as a competitor to Confluence and other wiki/document management system.
Speaking of GitHub Pages, this feature complements it perfectly. Now you can create a GitHub-powered website—including images et al—without touching git, in much the same way you'd use one of those "FTP web interface" panels on a VPS. Except that each upload becomes a commit, rather than just mutating some ephemeral folder somewhere.
With a gist you're able to quickly and easily upload a single file script (or multiple files).
Also once created you can clone it as a git repo and make updates and push back to it (e.g. add files etc). Also people can fork your gist just like git repos.
I like this approach rather than creating a "new repository" on github for small scripts or snippets because then your github profile doesn't get cluttered with small snippets and script repos and is reserved for actual "project" repos.
(1) It is true that this is more likely to turn GitHub into a generic file-dump place similar to DropBox. GitHub's infrastructure is sufficiently good to handle this, and this new addition is unlikely to disrupt the workflow of veteran users. However, since it is likely that some companies will use GitHub for file dumping, GitHub will be justified in charging companies a fee for particularly large repositories -- capitalizing on the file-dumping. I sense an alternate revenue stream coming in for GitHub.
(2) I've often run into situations in which I had written a small script and wanted to quickly turn that into a GitHub repo. To do so, I'd have to go through the online interface to initialize a new repo, and then make a folder on the command line, type a few commands, etc. Though it's a very short process, I couldn't understand why I couldn't just use the online interface to type up a readme and then drag-and-drop my script into the repo. The update smooths this work experience.
(3) Obviously, it'll make GitHub far more accessible to less technical users -- some users are intimidated by the Git learning curve, and this update makes them much more likely to use GitHub (and then slowly learn the ropes of using it via the command line).
(4) By inviting more non-technical users as in (3), it becomes more likely that (1) succeeds.