Sizzlecore has had an extensive hands-on with the T-Mobile USA version of the handset at a Dell event held in Singapore, and have published 3 videos of the device in action.
The handset will be shipping with T-Mobile software including T-Mobile family room, news room, T-Mobile TV (a rebranded Mobi-TV product) and also with the Telenav software package, which should take care of any GPS navigation needs until Bing gets turn by turn.
The above video is simply a brief overview. See two more after the break.
My one concern is, despite how good they slid-out keyboard is, the on screen keyboard in fact appears larger and more comfortable to use, which may make the slide-out feature redundant and the extra bulk not worthwhile.
Read more about Sizzlecoreâ€™s hands-on impressions, and see a number of pictures comparing it to the iPhone and Nexus One here.