MSN Careers has a quick article on job burnout, below are the symptoms:

1. chronic fatigue - exhaustion, tiredness, a sense of being physically run down
2. anger at those making demands
3. self-criticism for putting up with the demands
4. cynicism, negativity, and irritability
5. a sense of being besieged
6. exploding easily at seemingly inconsequential things
7. frequent headaches and gastrointestinal disturbances
8. weight loss or gain
9. sleeplessness and depression
10. shortness of breath
11. suspiciousness
12. feelings of helplessness
13. increased degree of risk taking

Here's my quick take on these from a Microsoft perspective

#12 - I've personally set my MSN status to “Doomed” way too many times.
#8 - Microsoft, like college, also has the “Freshman 15”.
#6 - This happens at most meetings I attend.  Unfortunately Microsoft conference rooms are filled with rat-holes everywhere. 
#4 - The joke at Microsoft is that the only non-cynical PMs in the company simply haven't been here long enough.