Yes, you read that right. The Dell Streak 7 has hidden phone functions and can sort of make calls.
That's the secret phone app you're looking at above. It's nothing fancy because the UI either isn't enabled or simply isn't in the system, but a dialer from whatever keyboard you're using will appear when you tap the bar below the Tablet, Call log, Contacts, and Favorites tabs at the top and let you input a phone number. Dashes are automatically inserted too.
The phone app also supports screen rotation and has a dedicated voicemail button and a call button that can be used to bring up the last number you dialed (for quick redialing).
If only calls could be properly made and received. You'll see what I mean in the video below.
If you're not into videos, then you just missed seeing my HTC EVO receiving a call from my Streak 7. Well, sort of. After the Streak 7 dialed and the call seemed to fail, the EVO started ringing.
Unfortunately, that's as far as I've gotten on my own. When I answer the call, there's no sound on the other end. There's actually no sound on either end. I haven't been able to get the Streak to receive a call either, even though the caller hears the phone ring and can even leave a voicemail message.
The solution could very well be right there in the system, as I found lots of phone-related activities that appear to do nothing when I try to use/enable/tap them, but I seem to have run out of the luck I was having with my trial-and-error method.
Assuming that it's really possible to get the phone fully functional, I've got more info in this Dell Streak 7 phone hack thread in the forum for anyone who wants to help.
Thanks to Fone_Fanatic for the original build.prop and EMList tips!