An interesting - and vaguely reassuring - note from Robert Half Management Resources: One consequence of a lousy economy is an extended job search doesn't look so bad to prospective employers, at least for senior managers. Executives the company polled say managers could be out of work for nine months before the duration started to impact their career.
I suspect the same is true for many professionals. While some people say there's no way being laid off doesn't work against you, I simply see too many exceptionally qualified people on the market today. They have real track records and can point to real accomplishments, but either their division was closed, or they were on the bad end of a merger (meaning, they worked for the company that was acquired).
And, I see a lot of executives talking about what a great time this is to scoop up talented professionals, cheap. You can't have it both ways: Either someone who's looking for work is valuable despite their being laid off, or they're not. I say they are.