Good posts from Drama 2.0 and Omar Malik on the continuing commoditization of social network solutions. Note that I believe social networking is still a good thing to have -- it's just that it's not a "build it and they will come" solution. You need to have an actual plan on how you will attract & retain users, generate content, monetize your site, etc.

BTW, Drama 2.0's blog is pretty new, but he (she?) has been commenting on TechCrunch for a long time. And his (her?) posts are great, insightful stuff.