The new layout doesn't seem to bother me to be honest. I for one don't mind simplistic-ish layouts, but then again I don't mind seeing a decent non-simplistin scheme. Take SMASociety
for example - lots in it but it all works really well together.
But when it comes down to it. Do we really need an amazing colour scheme for something which pretty much all you do is watch videos on? Of course we have YouTube channels which are another focus of the site, but they can be customised anyway. Another example of what I mean would be Google
- has pretty much always kept a three-colour layout: grey, white and blue (minus the logo letter colours). All you're there to do is search for stuff (most of the time anyway) so what's the real need to have a complex layout?
Now, there is the point of taking the idea of not needing a complex layout too literally. Most sites seem to get the balance of simplistic and usability right - while some don't. I think it depends a lot on what the site is about.
Another item I could include in the minimilstic category is Microsoft's 'tile' design on Windows 8 - but this thread is about YouTube.
So, overall I have no problem with YouTube's new layout - I'm only there to watch videos. So why be all glossy with the layout?