So, if you have an employee who needs to improve his/her performance, don't delay that tough conversation with him.
By addressing the issue with him early in 2010, you give him the opportunity to improve — because most employees want to do a good job. But, sometimes, they just don't know they aren't performing up to your required standards.
Don't wait to address the topic at the employee's next annual performance review. Instead, sit down with your employee in a private setting. Look him in the eye. Then, tell him what he does well. Thank him for that good work. Then, tell him where he needs to improve. Be clear. Be specific. Ask him if he understands, and ask him if he needs additional guidance from you about how he can do a better job.
Remind him that your taking the time to have this tough conversation with him means you care about him and want him to succeed.
Don't let a poor performer in 2010 make you so mad that over time you end up not wanting that person on your team. Address the issue soon and give that employee the opportunity to meet your expectations. And, if within a reasonable period of time, they don't, then don't delay the obvious appropriate action at that time.