Usually, as it was in the past, when Dell finally started producing systems supporting a technology is was considered mainstream. In reality, it's when the economics start to make sense that Dell's model, capital structure, turnover ratios, etc. all make sense; or maybe because Michael is back?
Here's a link to a quick video on Dell's announcement (blog, WMF, and MPEG respectively).
http://direct2dell.com/one2one/archive/2007/05/18/15193.aspx
http://media.dellone2one.com/dell/May2007/Tablet.wmv
http://media.dellone2one.com/dell/May2007/Tablet.mp4
The device looks very sleek, thin & light (can't tell the real weight from the video)... It reminds me of Motion's version. Doesn't look like I'll be running Visual Studio on it though. Looks like single spindle at best. Hopefully more spec's to follow.