You can change it to Bing, Yahoo!, Yandex in some regions and even Baidu in others I believe. Workarounds like the Disconnect Search extension and keywords are available for other search engines. Case closed.
Other topics talk about the same thing but yours start with a lie.
I understand what flexman meant, he would like to choose his personal choice for his browser use,as would many other users. Opera developers have been bought out by the google $$$ carrot. For those who want to use any other search engines other than the lame one's opera chooses that are not more secure than startpage or duckduckgo as they would like you to believe. So to those who want to customize their browser I suggest they look elsewhere as I have until opera developers allow users the choice they deserve as many other top browser developers offer. Opera developers used to lead but now follow the heels of google....too bad.