These days responsible web designers have to know the ABCs of SEO. I agree that there is an additional important profession of people who know the DEF-Z's of SEO.

If you're dealing directly with a client who has come looking for a website, it's important right up front to introduce the basic concepts. And this isn't easy, considering that much of the work is behind the scenes and must pander to Google's black box. As a web designer I've worked with graphic designers who have a hard time grasping that the elements of design for the web include more than just visual factors.

In a perfect world the client will have a post-launch plan for how they will get people to their website, but unfortunately many will do very little. It can be pretty easy to get the first 50 or 100 links into small sites, but as clients often will not take the steps to achieve this I think more than ever SEO professionals are needed. Hopefully when they start work they will find that the designer has at least had an SEO plan, even if it's rudimentary.

Hopefully SEO pros won't blame us designers for bad planning or poor execution when it's often the client who won't budget time for this or follow our tutorials for researching keywords or getting inbound links!