The S3 is supposed to get at least one more update. The S4 at least 2 updates. Only the S2 will be left at Jelly Bean (4.2.2). It doesn't matter if the next update is big or small - that's how Samsung's devices life cycles are planned. They're also commited to giving at least 18 months of firmware support too, so if a new huge update comes before that period they'll likely deliver it.
As Google releases updates approx. once a year now I guess the S3 will get this year's update but might not get next year's update (although Samsung are known for generosity with their updates so who knows).
I was also hoping for a huge update. I'd also like Google to refresh the UI a little bit and add features (not bloatware) to it. Also, improve multitasking management. I like being in control of what's working on my phone and using precious resources, but handling it in current Android is still very cumbersome.
I'm at a weird point where I prefer Samsung's skinned Android because of dozens of little things that are missing in stock Android and I'd have to install apps for those - with Samsung I get them out of the box. Whether it's battery percentage, flashlight button or customizable notification toggles - I used to complain about bloatware but with skinned Android I'd need at least a couple of apps less because that functionality is already implemented.
On Nexus 7 I have 4 apps installed just to do things that come with S4 out of the box, and N7 is just a tablet.
Another weird thing is, that skinned Android from Samsung is actually faster and less power-hungry than stock Android - the Google Play version of S4 lasts a few hours less than the international version, despite packing the same hardware. It means that Samsung managed to include optimizations that Google did not. And they're much needed.
