wtf #5: rivers? qua?

So, apparently when Rivers sang, "We Are All On Drugs" he wasn't kidding.  It's been a while since I've really and truly paid attention to Weezer...which I reckon is because even though "Make Believe" had some good stuff and The Red Album had some cool songs and some interesting, um...experimentation, maybe?, it's been a while since a really awesome weezer album.  But apparently through this not paying attention thing, I've missed Rivers' transformation into some sort of nerdy Rock Star, and weezer's metamorphosis into a bunch of crazy people.  Don't get me wrong, I totally dig all of these videos.  But, wow...this is the guy who wrote Pinkerton and then totally fell apart and lived in a house in LA with all the windows covered and just sat in the dark all day?  Check out this ass-kickin' version of their new single from Letterman:

And wait...what the hell? Pat's playing guitar? Who the hell is 
drumming? I can't even find anything on weezer's website 
about that guy...is he like the mystery fourth member of Green 
Day who plays all the guitar solos now? Is he in the band?  
Sweet version of that tune, though...love the horns. And then 
there's this one from last night:

weezer snuggies? What the fuck is that about? And what is Rivers 
doing? It looks like he's taking Rock Star lessons from some...um...
Rock Star, but he's such a dork that it comes off, well...super dorky.  
And of course by super dorky I mean Super Awesome! So what the hell 
happened? I do have one theory: I think it all started with this video:

Rivers' fantastic acting aside, not only is this one of the very 
coolest videos ever, look how much fun the man is having!  
And then there's Beverly Hills and...everything that has 
followed. Again, it's all good...but I guess the big question 
is...does this make their music better or worse? Or just 
different? I have no idea, really. But I guess I can't argue 
against a turn of events that causes them to do this fantastic 
cover mash-up:

I don't know...that's pretty awesome.