Device convergence

I've been considering a converged device for some time now; for so long that they were still referred to as converged devices then, or perhaps smart phones. Now they're just phones for business. The better of these devices are characterised by a number of features:

• email, usually through "push" technologies like Blackberry
• PIM (calendar, tasks, addresses) integration with desktop applications like Outlook
• full web browsing through Wi-Fi, or 3G where no Wi-Fi network is in range
• a range of input methods, usually including some form of QWERTY keyboard
• Microsoft Office tools
• extensibility, both through provision of extra flash memory and through an OS that allows other applications to be run on the device
• a broader aspect screen with sufficient real estate to enable email, Office and browser use

On the market now, or over the next quarter, there are at least four devices with different operating systems that meet these criteria:

• Nokia's Symbian-based E61
• the Windows Mobile 5 HTC TyTN, to be sold as the Vario II by T-Mobile, the SPV M31000 by Orange, or the Vodafone v1605
• Sony M600i, which runs on Sony's Symbian-based UIQ interface
• the Palm Treo 700

So why haven't I bought one of these already? Three answers: cost, form factor and requirement.
If you buy one of these devices under a decent 3G contract, its going to cost in the region of £35 per month, or £420 a year; you could get a PDA with all the features listed above but without the phone for half that price.
The form of these phones has, historically, not been conducive to both data entry and review as well as phone use. Some of the phones above are a bit cleverer, with sliding or tilting keyboards, but fundamentally the screen still needs to be big enough to browse on while the phone is small enough to use regularly.
But most importantly, are all the features that these phones provide really required? I do use the PIM information every day, but that's available on any mobile these days. I also use Word and Excel on the go and want to have other applications I can install. But email and web browsing? Is the always-on wherever-you-are internet really feasible or indeed desirable? Will I still be able to capture a 3G connection while I'm on the train and what advantages does it bring over plucked subscriptions to the sites I read daily? It's pretty rare that I actually need to get online to the latest news or extended link from the news I've downloaded to my PDA.
When I'm sat reading this news or making notes, is usually when I've nothing else to do but commute in an environment with poor network connectivity, so I want to be able to browse off-line. So what do I want my device to do? Would I make use of Wi-Fi and 3G if I had it?
As is often the case with anyone purchasing a new product, some features appear desirable but really won't be used that often even if you have them. So perhaps for the moment I should concentrate on a truly decent mobile computer -- a UMPC perhaps -- and a phone with a good camera and some memory for MP3 playing.