While I appreciate higher capacity for a lower price, I'd really like to have a 128GB iPhone. If it's an issue with chip size, surely the larger iPhone could handle it. For those who think it's insane to need that much space: You must not have kids yet. The videos and photos add up so quickly! To clarify I'm not the annoying guy posting them all over social mediabut I do store, print, and post them to a shared iCloud stream that also acts as a screensaver on my Apple TV.
The thing is it's difficult to spend time syncing photos off my device and then try to weed through them and decide which moments I want to keep on my device and which ones I'm going to archive to two external hard drives for safety. I'm hoping that iCloud Drive works well in this regard. I'm probably going to sign up for the 200GB plan at a minimum, maybe more if the price is decent. If it automatically moves my photos and videos over to iCloud every night then I'm fine with 64GB.
The other thing is that 1080p videos take up a lot of space. I wouldn't be surprised if the iPhone 6 records 1080p at 60fps, which will be even bigger. That and many AAA games come in near 2GB in file size, or uncompress to that size when installed (check usage). Many people who have streaming services also keep local copies of their favorite songs or albums. I know my local Rdio library is at least a few gigs, which comes in handy while on road trips when there is poor service and while flying. Then there's podcasts, Dropbox cache, things I've saved to Pocket, local cache of my Lightroom Mobile catalog, non-game apps that take up a lot of space like iWork and iLife, and don't forget the creeping terror that is the Messages cachethough that will have a setting to automatically clear in iOS 8. I hate clearing the whole thing as I can't reference recent messages, but then it takes up so much space otherwise. Can't wait for that setting which should typically keep another 8GB free.