No it's not useless!
To be honest I'm getting tired of the yearly releases for the sake of it. From the leaks it looks like the S5 will have a qHD screen, fingerprint reader, and the usual upgraded processor and ram. Probably a 64 bit OS but if you know a bit about 32/64bit you'll know it's pointless and just for marketing.
The fingerprint reader is also pointless. Again Samsung are doing it just because apple did and don't have access to the same quality solution. The iPhone solution works really well. Which pains me to say. But Sammy's swipe solution is just going to take longer to unlock and is the same fad that laptops went through 5 years ago. Only business laptops come with fingerprint readers nowadays.
Lastly is the OS. I don't feel that Samsung adds any value with their touchwiz extras. My phone has had Cyanogenmod installed from about 3 months in and I've started to think it's going the way of touchwiz and not adding any value.
I'm running the Nexus 5 ROM with xposed and that gives me all the features and modifications I need. Xposed is the real game changer here. The only problem is the stability. The S4 running a Nexus 5 ROM is never going to be as stable as the Nexus 5. The Nexus 5 is a faster device then the S4 and the battery life is far, far better. I now have one as my work phone and part of me is hoping the S5 doesn't have any ground breaking features that makes me want it. I'll then buy a Nexus 5 and lower my mobile contract saving some money in the process.
The Nexus 5 may not have a qHD display but within 6-9 months the Nexus 6 will with a more mature processor and better battery life. Until the Galaxy has a bleeding edge feature I don't see the point in having a bleeding edge device. And it doesn't look like the S5 will