Yeah I heard they were making a return but didn't realize they were an independent company now. Camera is definitely important to me but there are bigger worries over at Sony than a good smartphone camera.
I'd say their biggest worry is marketing.
Design is getting a bit old, but it's not like they're the only phone company using similar designs with small changes. Even though I've never had a problem with the glass design cracking, I wouldn't mind a different material for the back like metal.
The battery on their Z phones is already amazing, so they just have to stay the course there.
The displays are great, but there's always room for improvement. If rumours about a 4K display on the Z5+ are true, then... damn...
The cameras definitely leave room for improvement. The Z5 should be the first major update to their cameras in a few generations, so it'll be interesting to see how they perform. The M5 camera already sets the bar for the absolute minimum camera performance we should expect from the Z5, and it's already pretty decent.
Features like waterproofing are still a great feature to set themselves apart as no other major brands are doing it on the same scale as Sony. PS4 remote play is also pretty nifty... hope to try it one day.
Me? I'm probably going to sit back and see what comes out later. According to XperiaBlog, there will be a larger Z5 variant due out later this year, but due to the delay it might not get an IFA announcement. I'd love for a phone with S820 in it, but that would likely mean having to wait until late next year for a larger phone with it (be it an Ultra, or Plus, or whatever).
Ah well, wait and see. At least my Z Ultra is still chugging along nicely, so I'm not desperate to upgrade right now.