Since nobody cares to share, and don't get pissed at me these are just thoughts.

You will never be totally unique with dolphin such as a myspace or facebook without big time customizations. 1 million users and 10,000 concurrent is a big number. You're not going to do that on a single server. Some kind of clustering would probably be more suitable.

If you have the budget you might be able to hire some to do a bunch to your site. But bottom line is all dolphin is the same core programming. Myspace see more and facebook and the liking are unique because they don't offer others to download there code.

You could still potentially be unique, but you will probably need a lot of changes to the code, you will need a unique template, and offer unique features that other dolphin sites don't have.

You are also going to need a ton of space, a ton of bandwidth, which is expensive as hell when you are talking about this many users and add videos and look out. You will need some kind of sponsers to pay for this puppy, unless your budget is a few thousand $'s per month just for the fun of it.

Anyway just a few thoughts.