There are many great points in the article (and BTW I purchased the same cover - it has a magnet to turn the screen off when it closes and works a bit like an ipad cover) but there are some weird points. Well, a big one : no software phone by default.
Why should we need grooveip?
I have various SIP accounts, and on my laptop, I can use google voice to send call from the browser. I just wish the Nexus 7 had something better than "click to call" (to another device)
(and I wish it was possible to connect by SIP to google voice)
Just put some cash on your account and you can also send call.
The form factor is not really a problem - you just use the nexus 7 'differently'.