Permalink keywords do make a difference but they are way down on the list I think.

However if two sites had equal high ranking inbound links, equal page keyword optimization, equal domain name keywords etc except one site had permalink keywords and the other site didn’t then the one with the permalink keywords would get linked higher.

Obviously at the top of the game where its really competitive people do know what they are doing and they will do what ever it takes to get to the top - including using keywords in their permalinks.

The most important aspects to search rankings however (I believe) are these 2 things:

1. Constantly updating your website with new *quality* content with the revelant keywords prominantly featured in your article. What I mean by quality is that it actually something people can use to make their lives easier or can simply some how make them feel better in some way.

2. Getting links (with keywords) to your site from other high ranking sites.

The search engines love fresh new content. If the content is valuable and can add value to peoples lives because its something they can actually use, then other people will link to it after they read it.

But I believe that it is also important to pro-actively pursue quality links

Therefore I believe the most important things people should focus is on is constantly adding quality content with relevant keywords and actively seeking quality inbound links.