Google has made significant changes to SERPs by extending the length of titles and descriptions. Thus, instead of previous 50–60 characters, Title tags have been increased to 70–71 characters that are enough to fit in another couple of words. Also, Meta descriptions have been increased by 100 characters per line and extended to three lines so that such presence could better tell searchers what the page is about.
Nevertheless, Google still cuts the descriptions to two lines for many search results, so you may still see them coming in at around 160 characters at times. When there are three lines snippets, they are displayed in at 278 characters per line.
Note, that Google’s John Mueller wrote this morning on Twitter that this is just an experiment. Also, due to this article, he said in the Friday Google hangout, “I think what happened is we kind of increased the width of the column of the search results, on some devices at least. And in general, we try to match the length to what we’re displaying. So it is not that there’s any character count that we could cut off, but rather we try to figure out what fits in here, what can we show and match it like that.”
Thus, keep in mind that Google could reverse this test at any time so that it is a good idea not to base your SEO decisions on these numbers until it is known for sure if the test will become permanently changed.