Is it, though? I mean, youtubers, live streamers etc can be categorised under enthusiast media. The issue of ethics is still relevant in their cases also.
They're not breaking any laws, and they derive their income from hits. It's in their best interest to do whatever gets them the most possible views at any cost.
The only way that ethics enters into it is when (inevitably) a GIANT YOUTUBE SCANDAL hits one of the bigger personalities, and if it actually affects their viewership.
A likely scenario is that these PR/publisher ties to one of these streamers is exposed in an ugly manner and their subscribers feel betrayed and depart in large numbers.
But unless that happens, they have literally no reason to change their behavior, and plenty of good reasons to become more closely tied with PR.
Plus I suspect a fair number of them are savvy enough to understand that being transparent about their connections will let them get away with it - teen boys watching CoD videos often don't care about this stuff anyway, and they generate a loooooooooooooooot of traffic.
And yes, this certainly does have implications for web media in the future.
As far as the games themselves go, the nice thing about live video is that it doesn't lie. The commentator might, but the video won't. And in the case of live streaming, it's even easier to hear if someone is genuinely enjoying themselves. You can't fake real fun - one of the main reasons my stream was so popular is that my most common 'mode' of play was with a group of 3-5 good friends, playing relatively organized teamplay and generally fucking around like idiots and laughing a lot. Good vibes, basically, not rage.
Now, when we're talking about prerelease games being distributed to Machinima partners (this is going to happen more, not less), you're suddenly going to have the impressions of dozens of youtube posters live before the game comes out - for a game that is good, this is a hilariously cheap way for PR to get the word out about their game. I'd expect that shitty games won't get this treatment, because even someone who is a total shill will have a hard time selling that in video - something that's much easier to do in print.
Plus, keep in mind we have an entire generation being conditioned to not want to read a damn thing longer than 140 characters, who would rather watch a video. Long form text articles? Good luck!