Losing a programmer, what steps to take?

One of the programmers on our team is leaving for greener pastures. We will be going from 6 to 5. What steps should we take to ensure our development process continues to run smoothly, potentially while integrating in new blood.

We are currently working on a short release cycle with iterative development. Design - code - review. The person leaving was the most senior dev on the team, and would often give lots of feedback to the rest of the team, especially during the design phase.

There are few things you can do (in that order):

• Reevaluate your estimates, based on the experience of the remaining team members and the work items load balance
• Come up with a prioritized list of things you might have to cut
• Seek a suitable replacement (as aggressive as possible)
• Start a discussion with your company management on potential compensation package changes that would allow you to retain valuable human assets like the leaving guy

Update: Use this as an opportunity to build up your team. Throw a goodbye party for the guy that's leaving and make sure both he and the team are aware that his contributions were valued. :-) (And if you don't have a budget, just talk to the team members and you all chip in to get him out for a drink or two)