My sense from meeting Yahoo devs is that they are ok, in that they have the credentials, but didn't seem very passionate or excited about new tech. Can you bring up some examples where Yahoo is pioneering a new field? (search, media delivery, social etc, what ever Yahoo as a company is really excited and passionate about internally...)
How about Hadoop? Sure Google released the Map/Reduce paper, but it was Yahoo who wrote 90+% of the current industry standard.
What about Node.js? That's pretty en vogue right now. We are currently hiring Node.js engineers and have a number of core contributors in various parts of the company.
YUI and our other front-end work at Yahoo! is world class. People like Crockford are considered leading experts in doing quality front-end web engineering.
Our data centers are also cutting edge, I'm not an expert in this area, but I'm told we are at least on par with Google. Some of the new project are completely cooler-free, the whole building being designed to control heat and power flow.
Yahoo Search API (whatever its real name is... BOSS or something?) is also fantastic and much superior to Google's (which isn't even really a search api).
I was just commenting to a friend of mine recently how Yahoo is doing all sorts of cool stuff but doesn't seem to get any credit or credibility out of it.
The thing about Yahoo is that it's massively silo-ed. There's research teams doing fascinating algorithms and machine learning work. There's small hacker cores working on new crazy ideas and technology. There's also a ton of internal politics, NIH across divisions, and meaningless obstacles to getting stuff done.
As an example, I was at Yahoo for 5 years (2003-2008) working in the Search Marketing division. Tons of data, tons of optimization possibilities. Could we use the Hadoop cluster? No, for some foolish internal accounting reasons.
