My new MacBookPro will not boot after an upgrade to Yosemite

I upgraded my brand-new (month old) MacBook Pro to Yosemite tonight, giving it plenty of time to reboot itself -- twice -- finally putting up the login screen.

After logging in, I noticed that the WiFI was off, and even worse, it would not turn on, so I rebooted it again.

After rebooting, it went through another long boot, with a thin slider showing progress, and then it showed the login screen.

I logged in, and then was able to manually enable the WiFi.

However, the system fan was spinning quite loudly. I checked for any 100% or more processes, but the system was actually quite un-busy. There was no reason for the fan to be spinning full speed. The office temperature is a very mild 71 degrees.

So, I did a Shutdown from the Apple menu and left for dinner.

A couple of hours later, came back to boot it, hit the power button, and .. no response. The MBP was plugged in with power, so it should not be out of battery. I tried holding down the power button for 10s and then 20s of seconds: no joy.

Does anyone know of a way to power up the system? I tried CMD-OPT P R with power button, 10s and 20s, but still no joy. The system appears to be completely, utterly dead.

At this point, it's looking like a "bricked" MBP, and I'll have to take it to the Apple store.

Very disappointed in this OS upgrade experience, and Apple's apparent decline in quality control since Steve has passed on. I guess no one is holding production's virtual toes to the fire anymore, eh?