I always try to get the trinity - but - have developed my most successful site on a .org (not owning the .com)
Some things to consider when building a brand however are - can I go .org? who has the .com? what's on the .com?
I have one domain I would love to develop two word generic .org - perfect for the niche - but there is an adult site completely unrelated to the topic on the .com :(
I guess this is good news for speculators - .org's may be the 2nd tier domains - and 2nd tier now commands big prices...