So many social networks out there... It's hard to ...

I doubt it.  Too many people like isolating themselves into little groups...big groups scare them plus the bigger the group the more chance of arguments and disaccord. 

 I think the social groups will stay diversified not only based on topic but inside the topics.  For instance I'm in several John Denver fan/social groups.  There are some members in one that would never dream of joining another group because of a topic that might be brought up that they do not agree with but in the group they are currently in it would never come up.  Some groups are simply more open to discussions than other therefore keeping the diversity going.

Not even in beta yet, Google's sponsored SocialStream is aimed at interconneting existing social networks.  Socialstream would let you post content, such as photos, blogs, video, comments etc. to and from any participating network.  Sponsored does not mean it is a done deal and Google will launch it but it is in the works. 

There are also a bunch of other sites working on aggregating your social profiles.  Read more here: http://mashable.com/2007/07/17/social-network-aggregators/

How long will you have patience to meet new people, form new relationships and find new interests in the offline world?

And why do you keep all these obscure wrenches in your garage when you could use a hammer for everything? 

Yes, moving between social networks is a pain, and a lot of us are feeling the social networks fatigue. But upcoming standards like OpenID, FOAF & XFN, and established ones like RSS, are easing the pain of moving between different social networks. And there is a lot of grassroots thinking about which other standards are needed to let you move with ease between serviced. 

You don't have to keep track with all of them though. As you move to a new social network, leave some of the old ones behind you :) Natural selection is working here too. 

But, no matter what network I am on, I promise to always add you as a contact :) 

Convergence is already happening in facebook - the whole idea is using one identity with many networks (like yedda).

example: 
http://booksoncampus.com for example relies on your facebook identity to log you in

I have just joined facebook and I'm frustrated at the fact that I have access to people in my network but all the content is on my blog not on my facebook profile.

Maybe convergence doesnt need to happen but content needs to be able to be shared between different networks much better than it is now.