In short I believe performance based campaigns are raising the bar for publishers and forcing them to cater to the SME market as well which will help grow the entire industry.
In regards to the responsibility a Publisher has to it's advertisers my opinion is that they are responsible for both. We need to help create brand awareness as well as driving results for the client when and where possible. Generally the focus is on the actions vs the brand perception that a publisher creates but we should never count out the value of making sure a brand is known and seen as a leader in the marketplace as well.