I'm all for this. I don't get much time to play at the best of times, so having the option to watch other people's matches when I'm busy with other things would be pretty cool. I also think it would be an asset for new players, IF they set it up correctly. Ideally, I think it would be cool to have it mixed with the mentor system in some way. Maybe you could spectate PvP mentor matches, so that new players could see how veterans play certain jobs. Something along those lines.

I'm not holding my breath for this, though. Yoshi mentioned this a few times in interviews, but so far there have been no official announcements, which is kind of a shame.