Yes it is likely that ext4's days a numbered in terms of developing new features, however _today_ it is still the best choice for a filesystem if you don't run

Yes it is likely that ext4's days a numbered in terms of developing new features, however _today_ it is still the best choice for a filesystem if you don't run a bleeding edge kernel, and don't need the extra features. BTRFS is seen as the next defacto standard linux filesystem, and it has a ways to go before it can match the performance of ext4.