The dark news amongst all the good here at the Windows Phone Summit was that existing Windows Phone devices wouldn't be updated to Windows Phone 8. Instead, they will receive certain features from the new OS, most importantly the new Start screen experience. Microsoft calls the updated Start Screen on Windows Phone 8 the "marquee feature" and, as you are probably aware, it's coming to existing devices with Windows Phone 7.8. We got a chance to sit down with Microsoft's Greg Sullivan to take a look at the updated Start Screen experience on a very early build of 7.8.

Microsoft has done away with the "right rail" to expand Live Tiles across the whole horizontal distance and also added a new tile size, bringing the total to three. Developers will also be able to create the "large" tiles now, a feature that had previously been reserved for OEMs. To resize tiles, you just tap the lower-right corner to toggle them. The early build we were looking at showed the typical Windows Phone smoothness, though one final feature of showing a live preview during resizing wasn't quite working yet.

The net effect of the changes is a home screen that has gone from a relatively sparse-feeling set of large tiles to what could be an information-dense grid of icons and widgets. By our count, you can create up to 28 tiles on a single screen with no scrolling, which is eight more than you can pull off on the iPhone. It seems like a relatively small tweak, but it could transform the homescreen into a power-user's wonderland of information, if you're into that kind of thing. We're sure that it won't completely make up for not getting Windows Phone 8, but it should breathe some new life into some not-yet-old phones.