For me personally, no removable back and no microSD is not a deal killer. 128GB of that new super fast memory would be more than enough. I do have a 64GB card for my Note 4, but it's less than half full most of the time, and most of what's on there is a ton of music I never listen to. Since the next Note will probably have USB 3.0/3.1 Type-C to make use of that fast memory, I wouldn't mind ditching the SD card at all.
Removable batteries are just a safeguard to me. I like to think it makes it convenient to replace a worn out or dead battery 2 years down the road. But I always get so bored with a phone by that time that I'm replacing it anyway. I've never had to replace a phone battery.
All in all, I believe the microSD/removable battery crowd is a very small percentage of users. The Galaxy S6 looks like it'll be a record seller for Samsung, and that will put away any doubt they may have had about removing those features.
Anyway, still too early for Note 5 rumors. Maybe in 2-3 months. Well, there's the rumor that it'll be the first phone with a 4K display, which seems highly unlikely to me. That seems too big of a jump. If the Note 5 gets a resolution bump at all, it'll probably be something like the 3200x1800 that we see on laptops. Personally, I hope it stays at 1440p. The geek in me wants to see super high density displays, but practicality wins out at this point. Can't discern the pixels at all as it is now. I'd love an ever bigger display though. 6" would be nice. Oh and a huge battery would be nice. That new 5.1", 8.8mm thick S6 Active has a 3500 maH battery (can't wait to see the battery life on that) while we're stuck with 3220 maH T_T