I don't own one yet and these are deal breaking functions I need:

Must be able to share individual drives as separate drive letters.  As in Mapping networked drives in windows.  Seeing the drives mounted under a single drive letter breaks many of my application which rely on my network drives.  Don't take away the ability to access individual shares as individual drives in windows.

Seemless passthrough access to any printer.  No compatibility lists.  Ability for my printer manufacturer's software to access and monitor the printers.  Ability to scan directly from different applications.

Eliminate the umbilical cord tied to the pogoplug software.  

My recommendations to Pogoplug Developers: Buy and use a Belkin Homebase and Iomega iConnect.  That's exactly what I need.  But the Homebase doesn't support 64-bit Win 7 so it's dropping from the horizon.  Those devices offer a great base of functionality, just add your tweaks and special functions on top of that...

Your competition so far is the IOmega i Connect which allows me to map drives.