Zombie Good Times

The Sequoia Capital "RIP Good Times" presentation is about a year and a half old.

In the past few weeks:

• Quora - which most of you have probably never heard of - raised $11M at a $84M valuation.
• FourSquare is rumored to have gotten a $100M offer from Yahoo! with less <1M users.
• Groupon supposedly raised another round of capital at a $1.2B valuation.

These are all great companies, but - based on nothing but an uninformed hunch - these valuations seem awfully frothy to me.  Perhaps the good times have risen from the dead...