Google rewrites titles when required from content on your page... if your missing a keyword in the title it can easily rewrite your title and include it, as done with most searches these days.
Google will and regularly rewrites both
<meta name="description"> to match the search of the user, it does this by extracting relevant parts of the page, therefore there's no need to 'keyword stuff' or worry about titles being the perfect length.
Various online case studies have displayed that sites using meaningful titles have the best click rates which in turn can increase the rankings of the entire site due to the fact more visitors equals chances for gaining natural SEO from backlinks and social buzz.
- Good title:
How to design a website in under 59mins
- Great title:
How to design a HTML5 website in under 59mins
- Poor title:
How to design a website in under 59mins using HTML5, PHP, MySQL and WordPress
- Horrid title
How to design a website using HTML5, PHP, MySQL, WordPress and Photoshop
I'm not saying not to use long titles because they are perfectly fine too, even this page as you can see has a long title, but its also not stuffed with keywords.
A great title is made up of the most important keywords on the page and gets users clicking it, almost like a subliminal message.
Both Google and Bing do not punish for long titles, long titles become noise and may be ignored completely which means they will use other page signals. If you write hundreds or thousands of pages in this manner then it could become a penalty due to keyword stuffing, which still happens but far less and you need to be extremely aggressive for either to take notice.