Its actually an interesting thought what the value of the "myspace" brand provides. This is essentially a completely new startup. Keeping the "myspace" helps with the press as its sure to make news, but people will also dismiss it just for being "myspace" but would give a differently named startup a chance.
I think this is the right move though. People will dismiss it at first, sure, but others will actually give it a chance. If its any good, the "new myspace is actually pretty good" message will spread. If they didn't use the "myspace" name, a lot fewer people would use it at first and it would never gain any traction.
Watching the video, I'm certainly intrigued. Certainly too early to paint it as a success or failure, but if it *ever* was going to have a chance to succeed again, it needs something like this.