It seems that Google are looking to change from http:// to https:// for anyone doing a search over the next few weeks, making searching easier and safer.
According to Google Product Manager Evelyn Kao, who wrote in the Google Blog saying;
We’ve worked hard over the past few years to increase our services’ use of an encryption protocol called SSL, as well as encouraging the industry to adopt stronger security standards. For example, we made SSL the default setting in Gmail in January 2010 and introduced an encrypted search service located at https://encrypted.google.com four months later. Other prominent web companies have also added SSL support in recent months.
The only when a search will go through the http:// setting is when they are signed out of the Google system, otherwise it will be https:// all the way from now on.
Source [The Next Web]