For years as a website designer, I struggled building sites that both fit in Internet Explorer and Netscape.  The entire time, I didn't care who won the browser war--I just wanted someone to win NOW and the other to go away.  The increased work, stress, and money spent to build the same thing twice was frustrating and, in my opinion, unnecessary. 

The search engine wars are starting to remind me of those days as a designer.  For quite some time now, Google has owned the search engine realm.  The other main players (Microsoft and Yahoo) were worth the hassle, but not completely necessary to your marketing strategy if you could obtain good listings in Google.  My basic motto has been  get good rankings in Google, let the others fall where they may until I get around to them. 

However, it seems as though Yahoo is holding all of the cards as of late.  While holding off Microsoft's public attempts to acquire them, Yahoo has been negotiating with Google to outsource contextual ads in their search results.   

If Microsoft is able to acquire Yahoo, it may give them enough power and market share to make an actual legitimate attempt at competing with Google.  However, if the latest news proves true and Yahoo and Google are teaming up, then it will seem as though Google's dominance is here to stay. 

What is your opinion:  Does having two search engines split the majority of the market share benefit the SEO community or would you rather see one dominant search engine that you have to deal with for rankings?