Would that be pronounced "Touch-Us"?
I can't see too many applications where multi-tasking is a "must have". Maybe being able to keep pandora or slacker up while I'm running my gps software, or answering a text, or email, or even web browsing; but I have an extensive library in the ipod app as well so I'm able to make do. It doesn't seem worth the trade off of lower battery life, I already have to think about what i'm doing on the phone come evening time as I'm usually around 35-20% life; I had to place a dock in a convenient place so that I can charge the phone when i get home from work but still have relatively quick and easy access to it in case of calls or otherwise.
I'd like the ability to add background images to the home screen, categories would be nice (that was my favorite JB feature). Spotlight helps with 20 pages worth of apps but 90% of the time I forget about it until I'm halfway though swiping, and I mostly use spotlight for finding apps, as I forget it searches contacts, mail, music, etc. I find myself going to the specific app to search. I'm not too concerned about a unified mailbox, I don't use that view much in my mail.app on my MB. If they did implement that feature, it would NEED to be smart enough to reply from the mail account that the message was sent to.
My wife and I both have iPhones so the need for multiple user accounts on iPhone I don't really see as a big deal, I can see how it'd be useful on an iPad though. If that did come to iPhone what I'd like to see is a way to make a "games only" profile that I could switch to when my kid wants to use it; but then we just bought him an iPod touch, which pretty much negated that need.
Changes I'd like to see to the lock screen include being able to decline a call and still be able to use the phone. When my phone is locked, if someone happens to call you answer via the unlock slider. If you press the sleep button to decline the call, the slider will still answer the call. As other people have mentioned I'd like my push notifications to stack, closing a text should not remove the badge from the messaging app nor should it mark the message read, especially for long texts that are truncated in the notification. I'd like to see a way to manually set the tone of a push notification as well. I use the Meebo app for instant messaging and it's audible tone is the same as whatever you set your text message tone to; and I treat those notifications differently so I'd like to differentiate between txts and pushes.
Another change I'd like to see to the mail application is a way to hide or collapse folders. I work in IT and about 25% of agents I support have iPhone and that number is steadily increasing. One complaint I field quite often is that some users have elaborate filing systems and their list of folders requires them to scroll for ages to find a folder that they're looking for. Sticking with folders, it'd be nice if there was a way to "force sync" a folder while you're looking at it to bring up items that are older than your sync is set for (4 days, or weeks, if you're set to only sync 3 days back). Even if it's a temporary sync that only shows the messages until you leave the folder. For me, there have been many a time i've had to change my sync setting to "unlimited" then have to sync my entire mailbox, forward the email i was looking for, then change my sync setting back to 3 days.
I cant' really see anything "BIG" that could be added to this release, cut/copy/paste and push notifications were kind of the only new features that I REALLY wanted. Most of my requests would be more along the lines of refinements. The rest I have, and could probably still, live without.
