I'm actually really looking forward to this. I do have a 30" widescreen CRT TV that I used to use for classic consoles, but the thing is a beast and currently in storage (though I've got it ready if I ever do get a chance for a dedicated setup some day). That means I'm stuck with the HDTV, and although I think older consoles look ok on it (it's an older LG plasma), they definitely don't look their best.
I have a Retron 5 and am pretty pleased with it overall, so for a quick way to play old Atari carts on a modern TV at a low price, this will work pretty well for most people. As long as they keep that price around $50, I'm almost willing to bet that there are plenty of people out there who have some old 2600 carts that they've picked-up over the years or have hung onto since they were younger (probably long after their original VCS or 2600 Jr. failed) that would pick something like this up in a heartbeat. With the also-HD Retron 1 HD selling for $40, there's no reason that they shouldn't be able to keep the price-point low, although they're probably expecting the demand for the 77 to be of a much smaller scale.