My wishlist:
That the rumored dimensions and bezels from the concept pictures aren't true. The bezels looks massive, which I'm surprised about because I thought mobile manufacturers were moving away from. It's also bigger than it needs to be. 4mm taller to be exact. It should be at least 4mm shorter than the rumored dimensions. Screen to body ratio should be no less than 73%.
Naturally you think it would have the SD820 chip, but I figured they really want to blow people away, I hope it has the SD821. If it in fact has the SD820, and not many other notable features, I don't see why I wouldn't buy the Oneplus 3 instead. If this is supposed to be their first real phone to compete against the other major flagships, it's going to have to be something other than their previous Nexus developer reference phones.
Although it will most likely have a 3450mah battery, it needs to last longer than you're average 3450mah battery (which are disappointing), and the previous Nexus 6p 3450mah battery. I had the 6p for a while, and it regularly would end up at 15% by the time I get home from work. Now I've been using the Redmi Note 3 for a while, with a 4000mah battery, and it ends up at around 70% by the time I get home from work. Too sharp of a contrast even when considering the specs.
The only piece of software that would stand out to me would be a merging of Google Allo and Google Hangouts to compete directly with WhatsApp. Whether or not that's happening anytime soon, it could make massive waves if they were to introduce it during the reveal on October 4th.
Pretty basic stuff. If they really want this to fly, it's going to have to offer something that stands out from the competition. Perhaps there's something they will reveal or offer I haven't thought of yet, or didn't know I wanted. If it's just a rebranded mediocre Nexus phone, don't think I'll be interested.