When we do a new client, we tell them register your biz name in the .com and then the .us, we then say .net and .org and .info are lesser domains you may want, but we push .com and the .us, if they're a US business and doing most of their business in USA. Then for acquiring keywords, we explain they may want to consider .biz besides the above names, so our order of importance is
.com
.us
.net
.org
.info
Then we add .biz for possible keywords to consider.
Also, for pure position, the .org will pop over any .com all day, and a .gov gets absolute priority, that's the real algorithm the top SE's use, keyword look for .gov, then no .gov look for non-commercial use (.org) then look for commercial (.com) then country code the searcher is in, that's the algorithm all SE's use.
Most 'new businesses' starting to really get into the net, are small or new businesses that may have dabbled in internet marketing, so they may own their name in the .com already, then we make sure they get the other major TLD's relevant to US businesses, then we start to acquire the keywords they need and most are unregistered GEO+keywords, the same phrases they and their competition BUY via PPC.
So for major businesses, and single keywords, the strategy is not the same, but who is acquiring new major companies? No one, all the big corporations now have SEO and SEM guys making over 250K a year to oversee their years old operations, so all the growth today is in small and mid sized businesses that have geo-centric needs and .us is more important in our main market (USA) than a .net is