The LG G2 and some other devices already have OIS and the difference is pretty remarkable when it comes to having a stable image. The quality of the photo doesn’t really change that much, but the precision and stabilisation improves massively with this feature.
This feature was almost on the Galaxy Note 3 according to some rumors prior to release, but Samsung scrapped it due to not having the necessary components and scope to actually add the feature, it may be the same case for the Galaxy S5.
Samsung’s small problem when adding features is they need to be able to scale the production above their target range of sales, for the Galaxy S5 this may be fifty million units in one quarter. This means features that are new and not exactly the most readily available cannot be implemented.
Another example of this is the fingerprint sensor Samsung was apparently thinking about adding to the Galaxy Note 3, but since the scale of that device needed to be around 20 million a quarter, they could not work to make that number viable on the time they had to implement.
We are not sure if the Galaxy S5 will have a fingerprint scanner, our gut instinct is yes or in some way Samsung will upgrade security. Apple has obviously shown the demand with TouchID and shown they can scale this project to the mass-market.
OIS is not the biggest feature we are desperate for on the Galaxy S5, the metal body, higher-resolution display and new possible software enhancements are more exciting and more relevant to a users experience and love of the smartphone.