It's all about making Yahoo feel more personal. More like your friend. Mayer is trying to personally invite you out for coffee to and talk about the fun she had bashing out their logo.
I'm sure there are refinements that are happening behind-the-scenes after Mayer's "weekend". Hopefully resized forms of the logo will still get some TLC - the public doesn't generally notice when those things happen.
Remember the demographic that Yahoo survived upon - women. Non-geeky grown-up middle-class women. That's why the new logo reminds you of a department store like Macy's, or the makeup counter at Shoppers Drug Mart. That's who Mayer is targeting with this ad, even this blog. It's a huge number of people that most of the technorati ignore - Facebook captured that market practically by accident, and Pinterest is exploding because somebody finally thought to actually aim in that direction on purpose. And what's pinterest about? Craftsmanship. Craftswomanship. Getting your hands dirty on a fun little artistic project.
Like making a logo.
Latter-day Yahoo has always found strength in ignoring the geek elite. They lost the geek elite a long time ago. This includes you, design geeks.