1. Showing hand-drawn versions of your logo in what clearly is set in hardly-modified Optima (a typeface designed way back in the 1950s) makes me cringe. Why show fake process work?
2. No one is impressed when the manager does the job of their employees. For one, it implies that they don't trust their employees, and secondly, it makes the job of designers look like a fun hobby that anyone can get into. The result is exactly what happened here: an utterly boring logo redesign that looks just-polished-enough to make people think that Marissa Mayer is some kind of genius, yet simple enough to make people think that true designers bring no value to the table.
3. The whole 30 days of logos schtick was awful. Good artists know that the worst thing you can do for yourself is show too much of your own work. After a while, everything looks same-y and the weaknesses begin to become more apparent. The whole concept reeks of indecision and a pray-to-God moment that one of the logos would have such a huge outpouring of support that the Yahoo! team wouldn't have to make up their own minds on a vision.
4. The bevel isn't even customized. It's a preset Adobe effect. Pretending like the Y shape in the bevel was intentional is horseshit and obviously a desperate attempt to give some sort of conceptual significance to what is otherwise a completely forgettable design.
From this I remember various things you may remember too:
1. The Google favicon. They did thousands and the one they choosed was crappiest one. They had to change it later.
2. The Google favicon with blue. Also, they did silly tests. Now that thing is gone.
I think this post resumes it well http://stopdesign.com/archive/2009/03/20/goodbye-google.html