For all the effort that has gone into it, Orkut is a remarkably boring place... about as exciting as Stanford University on a Monday night before midterms. Maybe they shouldn't have started the site off by having Google employees invite their friends -- far better to give the initial accounts to carny freaks and sex workers instead. It's doubly pathetic to see so many "software intellectuals" linkwhoring as if their whuffie depended on it. "I just expanded my social circle to 3,582,191 people! Whoo!" Way to go, sporto. You know your life sucks when you use the word "friends" primarily as a technical concept.
It may take a few harried weeks for them to adopt the best that Orkut has to offer, but Tribe.net is a thousand times better socially, and for those into subcultures (esp. in the S.F. bay area), it kicks butt and takes numbers. Look deeply and you'll find all sorts of cool private events. Look deeper still and you'll probably get some. I'm sure they'll appreciate having a site like Orkut to borrow ideas from, though.
I know I'm going to regret this in fifty years, but I'll say it anyway. I can't think of another kind of social software application of this ilk that I want to see. Not one. Really, the problem is that you're practically expected to join them all. Yeahright. Good luck. I like keeping up on the new features, but at a certain point, why join yet another nearly identical service after you've made your initial investment of your time? Enough is enough.
Ultimately, people will either want just one site of this ilk that works for lots of different people in lots of different ways (unlikely) or they will want to have ones that tie together and allow interaction between services (more likely). If Orkut really wants to make a difference, they should consider the idea of being highly customizable *AND* geared towards interacting, at least with other sites running Orkut's software on their server. By itself, Orkut is just another particularly senseless part of Google, Inc., but if they actually empowered their users to do cool things with their software, you've got real possibilities. Spread the seeds and let a thousand Orkuts bloom.