Question if I am comfortable using my HTPC and wireless keyboard what does this get me? I am not saying the price is not right but I am trying not to waste money on impulse buys if you catch my drift.
On another note, no device should not have dual band mimo if a $20 dollar arm+1gb ram+8gb flash can do it.
Ultimately, depends on what the OS is. If it's limited like Chromecast, you get what you get. If it's Android like the existing Fire TV box, then we can most likely sideload all kinds of goodies, which would make it easily worth the $39 MSRP, not to mention the $19 sale price.
It has voice search (via app, or you can also buy the $30 voice-enabled remote as an accessory - they just include the basic non-voice physical remote, which is already a step above the Chromecast) plus over 200 games at launch, as well as the ability to use various gaming controllers, which is pretty nice. This is basically like an iPhone for your TV...it comes preset with certain channels & apps, you plug it in & use it, the end. So it's a convenience thing really.