All of my designers have sent me professionally documented PSDs and HTML/CSS. They often use some kind of HTML5/CSS3 Framework, like Skeleton, Twitter's Bootstrap or the popular HTML5 Boilerplate. That way they save a lot of time, but there are many tools that automate the process of writing HTML/CSS.
I hope that my Designer(s) deliver(s) nice HTML/CSS, so that I can convert it to a working template and then focus on writing the application. I often tweak the PSD and export the slices, because tools can't beat humans when it comes to optimizing the output size of the HTML/CSS.
It's commonly known and understood that the delivered HTML/CSS is of prototype quality, except when labeled "professional template". The time writing HTML/CSS is better spent at documenting the PSD and communicating how the UI-State transitions should be implemented, when the designer isn't good at it. Now you may see that there isn't a silver-bullet.
And don't forget, that when you work with a Developer, it is entirely possible that he doesn't know dime about Frontend Development too, because he/she might be Software Architect, a Backend Developer or something else that isn't involved with HTML/CSS.
Most Developers advised their Designer friends to avoid graphically intensive PSD in the past. Don't do that. With CSS3 it's almost possible to create image free templates that look like the PSD. Don't limit your Designers, but ask them to also think about the UX and colorscheme.
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It's my opinion that UI-Designers should also be professional Front-End Developers. And that Back-End Developers should also be Software-Architects. Being an expert of a fraction of a disciplines may be meaningful for Facebook, but certainly not for the common Start-up (imho).