I don't think you should change all the page titles on your site to 40 characters or less just to conform to Google's new local SERPs.
The 40 character limit is what Google will show not what you are limited to use. The best advice I can give you is to be "true" to your page titles. If you need more then 40 characters to properly let search engines and people know what your pages are about then you should. Just don't add (stuff) an extra list of keywords to the end of your page titles.