If you?re goal is to own this smartphone market and you know you have to have the carriers love you, then I?d go for the high revenue generating features. I believe these to be trending toward music, gaming and data communications. Let?s talk convergence. Most folks like having separate products because to this date they?re usually better, but the moment you combine something well you?ve got it.
Music.
First I think you hit ?the? audience if you can combine the iPod and the Treo. Mobile music is going to be huge. Our society has been disconnecting from each other for a long time and the idea to pop some head phones in and essentially hide from people has really caught on. Not to mention you?d finally give those idiots that walk around with their Bluetooth headset always in their ear a decent excuse. The win for the carrier is when you provide over the air downloads of music. (Hell, if you really want to entice them make it possible for Peer-2-Peer software to work and the data traffic will go through the roof. Imagine if everyone had their music on their phone, which is always on and always sharing away their, um? files…)
Next up is gaming.
There is a generation that most product designers don?t even understand. They grew up with a computer, a gameboy and the ability to connect with their friends over email, IM and SMS. This is the generation that actually interacts with each other, albeit not via voice or in person. By providing a gaming platform where folks can play interactive games and communicate with each other such as with services like Xbox Live, you?ve created a product that appeals to an up and coming consumer group and again can drive a tremendous amount of revenue depending on how the carriers charge for that bandwidth.
(Note to carriers: I love unlimited bandwidth. I don?t think the answer here is to try to get back to charging me for every kilobyte used, but if you price it right you?ll still make a profit because everyone will want the data part of the plan. You?re total ARPA should still be able to stay stable or increase depending on how you price the package. For example, most people want voice, but hardly use the minutes. The magic price point is somewhere between $30-$40, and you can then tack on the $20-$50 data package, which puts your ARPA way up. The key is having enough things to use that data package for to warrant it being added on)
Now, Nokia is obviously heading down this path with the ngage, but have you seen that thing? It?s huge. Again, design will rule, just ask Steve. The other key I believe is providing a platform for the major developers to easily port to from their existing Gameboy or upcoming Play Station Player (PSP) games. As for other data communications, simply put, give away IM software and make SMS actually work (this is something the carriers need to fix; i.e., guaranteed delivery of failure notification).
email
Additionally, we need to rethink email on your mobile device. At work (or could be school) and home I may prefer to read my email on the web so that I can type more and read the message easier. However, I also email a lot during the day (revenue driver for carrier) and often get emails out of sync between the server copy and the one on my phone. Meaning, if I pop my email account to my web email client then the message is no longer available for my Treo to pick up, and if I didn?t finish reading everything I popped, then I?m out of luck until I can get back to that website. Now, I realize I could set that pop to ?leave messages on the server,? but I still have the scenario where I may pop the email into my web email, not finish reading it all, then pop it into my Treo (since it?s still on the server) and now have two copies that I have to go and delete. This is a pane. I think Danger?s Hiptop is the closest. On their platform if I delete an email on the website, it?s also deleted from my mobile device and vice a versa. This is cool, but I?m forced into their web application. What if I want to use Thunderbird or Outlook Express? Here I think you?re making progress, but haven?t made the giant leap. Let?s get together with Good Technologies or RIM and make it all happen. As you may note I didn?t say anything about web browsing. Well, this is so screwed up I don?t know where to start. It takes a day to load one web page and for some reason even with cache it takes half a day to go back to a web page I already visited (regardless of carriers). In summary, you?ve got your work cut out for you, but there are some great opportunities out there and you are the leader. I?m looking forward to the Treo 6000. Let me know if you want any help.

• If you want to be really cutting edge and also have something ahead of the curve release a Treo that only works on WiFi (or have dual radio if carrier allows you). The day I can use my treo on a wifi network and call with Skype is going to change the world