Term Limits for CEOs?

I sometimes wonder if it would make sense for companies to set formal 7 to 10 year "term limits" on their Chief Executive Officers. Doing so would have several advantages:

1. For every genius forced out, there would be far more executives who reached their peak performance years before the departure date. The term limit would be the board's safety net, permitting an exit without rancor.
2. The practice would give added weight to succession planning.
3. It would encourage potential contenders to stay on in the hope of eventually winning the post.
4. It would permit fresh air to enter top management and perhaps even reveal questionable practices which have been suppressed.
5. It would motivate the CEO to get key projects completed before the departure date.

I would add one more item: Once two years have passed since the CEO's departure, the board could bring the person back. Such actions should be rare but there are times when the option may be needed.