Tapping on Tweets in Google search will take you to Twitter where you can view that tweet and also find related Content on Twitter. Search results are triggered by Twitter’s search or tweets from specific accounts of from specific hash tag results.
Google and Twitter both companies confirmed the integration via their blogs. Blog posts also confirmed that this integration is only available for English language in US. In next few months, it will also be available for desktop searches. Companies are also working to bring this for other countries.
This integration will surely put Tweets at visible places in eye catching manner. So, Twitter will surely get traffic from Google search. Now, its up to Twitter to convince new visitors to be a regular Twitter user.
Source: Google Blog