Seriously upset that Bing is no longer able to be selected as the default search engine, and frankly I'm not going to settle for a manual add even if I could set manual search engines as the default.
I did get an explanation, but unfortunately I'm legally not allowed to share it with you. I can tell you this much: Opera didn't swap Bing with DuckDuckGo because they felt like it, but they did so for a reason. IMO Opera's non-communication policy often offends people and isn't the best idea after all, but as I'm not working for them, I can't change that.
I'm going with solution number 2 (out of my mentioned comment). I was reassured by Opera's devs that they really want this to happen themselves. They just didn't come up with a solution yet that prevents third-party programs from fiddling with your search engines.
All I (and probably most here) want is the ability to select Bing as the default search engine in the Search Engine settings menu, drop-down style. Besides maybe Yandex, I struggle to see what other search engines would even be meaningful to add. Bing has 20% of all search marketshare now. If there's some legal conundrum or some under the table deal that Opera made which has resulted in Bing being removed, Opera better settle it quick. Count me out if it means that Bing is a second class citizen when it comes to search engines on the browser. In the mean time, I've switched back to Internet Explorer, though I'm none too happy about it.