Is Yahoo laying off 1,500 people? Or 3,500? It all depends on how you define "layoff." A commenter on Silicon Alley Insider has a theory on Yahoo's layoffs, which the company may finally announce in today's earnings call:

They will likely do a public round of layoffs soon, but since they are currently preparing for annual reviews- definitely cutting the bottom 10% who will be left after the layoff... but in addition- they will likely be as harsh as they can and some good people who are not performance problems, but are not the water walkers will feel undervalued and leave due to their review. This will likely get them down by another 1000- 1500 heads by mid year 2009.

What's interesting about this rumor: It fits with what we've heard about Yahoo CFO Blake Jorgensen pushing to slash employees' severance packages. By disguising layoffs as negative reviews, Yahoo management may push employees to leave, sans severance.