Google has a new design and with that your title tag length, the blue clickable link in the Google search results, may be impacted.
Pete Meyers from Moz posted New Title Tag Guidelines & Preview Tool. He says the new title tag length is not set at 55 or a specific length, but ranges between 42 and 68 depending on Google's algorithm.
Here is the distribution chart on how likely it would be a specific character length:
I should note, this has no impact on rankings. Just because Google cuts off your title tag, it doesn't mean it isn't used in its entirety for rankings. But it does mean that your title tags may be less click friendly.
A WebmasterWorld thread is seeing a lot of questions about the title tag changes.
As martinibuster put it:
This is just the display of the Title tag, not the consumption of it by the algorithm. So, as you already noted, a shorter title may be more general. I'm not changing anything for Google. If a slightly longer title makes sense then that's what's going in the title.
This doesn't really change anything for me, though. I don't do exact match longtail titles. Prefer to match it generally in the title and more exactly in the text of the content.
Check out the Moz post for more details.
Forum discussion at WebmasterWorld.