It's called a proof of concept video. Devs do it to lay out the general concept for gameplay, or to display the style they want to go with for games. It's done fairly often in the industry (Valve made proof of concept videos before ever dedicating actual development time to HL2's physics based gameplay. If I'm not mistaken, SW: The Force Unleashed was greenlighted on one guys proof of concept video). It makes sense because no developer is going to spend months working on parts of an actual game that either may not work, or they may never get the greenlight to do in the first place.
And frankly, with the general lack of innovation coming out of Japan and the halfassed Wii and DS titles they're prone to spitting out into the market, I find Japanese developers are almost getting lazier than American companies. Very few of them are willing to try anything new, or spend the amount of time it takes to make a game right these days.
Back on topic; I haven't played the new SH yet so I'm not going to say anything bad about it. Just like you shouldn't if you haven't played it. I've played a lot of games over the years that were better than I thought they'd be and just as many that were worse than I thought they'd be, and unless you play it for yourself you just don't know which is the case.