- make phone calls and send text messages
- a usable webbrowser
- a good selection of useful Apps
- capable of replacing a mp3 player
- being able to take quick pictures
- a map application (not necessary route planning)
- replace any USB Pendrive (being able to mount it on every device)
- capable of sharing an Internet connection (USB, optionally WiFi)
- use it as a remote for other devices (DLNA and similar things)
Making phone calls and writing text messages is a pretty obvious one. Also a decent webbrowser supporting current standards is an important feature. Useful Apps to add features and customize the phone to ones likening is great. Apps like Shazaam, Grooveshark, Dropbox, WhatsApp, Skype, Facebook, aso. are all great to have on your phone. Usually I settle around 40 Apps on my current Android mobile. Especially Dropbox is a very essential App to me as it makes exchanging files between devices very easy.
I like to have a Map around. It has proven to be a handy thing at times. I don't care much about what provider it is of. I usually prefer Google Maps as they have a lot of additional data. But it's not as important to me. I just want it to show my current position and the streetnames to find something. In a big city this is a very useful thing.
I want my phone to replace other devices I used to carry around with me. So replacing an MP3 player is an obvious thing. It doesn't necessarily need to be the best player but it should get the job done in some meaningful way. For example I'm constantly confused by the Windows Phone 7 Player. I need at least double the time to get together a playlist of what I want than on Androids default player. The WP7 player is capable of playing what I want but I find it rather confusing to get there.
An other device my phone needs to replace is a quick shooter for pictures. Usually current generation phones are good enough for my taste. I just like to take pictures of funny things or something I want to remember or post on a social network to share with others. For serious Pictures I rather take a better Camera thats likely more expensive than my phone anyway.
Yet another device I want to replace is a Thumbdrive. My phone should be able to be used as one. This has already proven a very good feature multiple times to me. Every phone that isn't able to do this is out already. I usually don't need much space, a GB or two should be enough for this.
As my phone already has Internet access I want it to be able to share that with my other devices. I usually use it over USB on my Netbook. Most of the time this is enough but it's still nice to be able to also share the Internet over Wifi. I don't want to carry around yet another thing so I have Internet on my Netbook. Like right now I'm sitting in a Train on my Netbook and using the Internet of my mobile phone to write this. And I'm listening to music played by my phone as well. It's great what's already possible and I can't wait for what's next.
As more and more devices support DLNA its really handy to have a remote for them right in your pocket. I'm looking closely at the DLNA features on all my new media devices.
So with these features OS choice is very slim. Windows Phone 7 and iOS aren't capable to deliver the features I want without some great effort like Jailbreaking on iOS. Android is the only bigger choice left. WebOS as well as MeeGo would be nice but just don't have the needed traction and with that support. Hardware wise I'm against taking a device with your contract as these aren't as cheap as they seem. And the lockin you get is even worse. Most of the time you pay more in the end. So Carriers get more money from you and have you locked to them. Great for them, bad for you most of the time.
I think in the future Smartphones will also start to replace other devices we have. Like your computer at home. It just needs a dock where the monitor, mouse and keyboard are connected. On-the-go you just need a cheap Netbook shell to place your phone in. As our phones get more powerful this will be enough for most people. Want to watch a movie? Your DLNA phone will stream it and your DLNA capable projector or TV will make a cinema experience out of it. It's gonna be great :)