White Labs Yeast longevity?

I got a vial of White Labs yeast American Lager strain from a friend of mine. Problem is, it's expiration date was Dec. 10. I was ready to brew my first lager so I warmed it up and pitched it into a 70F degree starter made from 1 pint of water boiled with 1/2 cup of DME. After roughly 10 hours, no signs of life are evident. I wanted to boil my wort tonight but now that plan is off. Is it likely that this yeast is dead a month after its expiration date?

Lagers need a BIG starter. Check out the site called mrmalty.com. There is a yeast pitching calculator, and I would guess that you should have about a 1 gallon starter for a lager, especially for expired yeast. The yeast will still be good, but it'll take a while for them to revive and ferment the starter. 10 hours is really too quick for a starter anyway- a couple of days is more realistic for an ale yeast starter, and 5-7 days for a lager starter is more realistic. I like to make a small starter like you did, wait a day or two and "step it up" by adding another quart of 1.040 wort. Let that ferment out, and then do it again. Then, I stick my lager starter in the fridge (once it's fermented out) and decant the spent wort. I pitch the yeast when the yeast is 48 degrees, and the wort is 50 degrees for all of my lagers.

Hoped this helped!