I actually sort of dig this design if they could make some general improvements.

If they could, they should make a successor (e'cho^2).
It should have Dual 800 x 600 SLCD/IPS, at 4.9" size (205ppi).
When opened in landscape it'll be: 1200 x 800 (HD), at 7.0" size (205ppi).

But they also need to make some design improvements such as vurtually trimming off all the bezel (yay!), make it more thinner, and use an aluminium-unibody construct.
Going by such a new design, the phone will still be quite pocketable (130mm x 68mm x 14mm), but remember it'll negate any reason for you to carry a small (<8") tablet which is a big plus.

Also update it to Gingerbread, perfect the dual-tasking software, improve the camera and screen quality, upgrade to Tegra2, and add a larger 1600mAh battery.

Just to show you how portable this tableting-phone could be, see how it compares to the Dell Streak and EVO 4G on these realistic illustrations I just designed:
http://img41.imageshack.us/img41/3166/echo2c.png
http://img641.imageshack.us/img641/4233/echo2d.png