I think this would make a lot of sense on platforms that undergo massive fragmentation(all fingers pointing at android here). Browsers are also fragmented , but websites like Can I Use It[1] should be able to reduce the problem to a manageable extent. I love the idea of reproducible bugs. Because often the hardest part of solving any bug is first being able to reproduce it followed by finding the source. Since I presume these containers would also help in reliably reproducing those one-off bugs which happen only on first install/ first open / on some other event.

[1]:http://caniuse.com/