This is a feature that could indeed be convenient, but will it sell a phone? There's a vast number of criteria on which to base a phone choice, and a nice-but-not-life-changing feature like this seems like an extremely tough sell by itself.

Here's what I think Sony should have done (and could still do): instead of building a phone with this feature, build a protocol with the feature. License it out to third parties, and watch as various ecosystems pick it up. Build, or license someone to build, something on Symbian, BREW, WinMo, or how about the obvious: an iPhone app?

A protocol would open the doors to a bona-fide advancement in Sony's gaming platform. A single phone is just an interesting sideshow.