The best part about your line of work is when you actually see results and things working and therefore you get to develop your own personal arguments and examples and case studies to justify you're actually doing something right.
This has profound implications on the way we as social media professionals look at our work and better yet, embrace it with every breath. I don't see any other way to truly make an impact than to live what you do and perpetually experiment on yourself and others to further increase your understanding about it. (I recently did a little stunt which to my surprise caught on and helped me learn a lot about what makes some people tick)
On a more personal level, I think the next step in working with social media is taking the conversation offline. It's about building a following on Twitter which you'll actually eventually meet in real life, because otherwise what good is it? Sure, the web has made geographic limitations obsolete, but if there's anything I've learned so far about human relationships is that nothing beats a face-to-face conversation.
Why this and why now? Because I think all these experiments we ought to be doing help us better understand the "why" of what and how we do things. The social media market is reaching a point where the people "who do Facebook pages" and who write "cool copies on Twitter" have to step up and know that all this has a goal and specific tactics that are more than your intuition. The goal is to develop relationships, both on and offline. And tactics are something you test, measure and learn with.
In social media and in human relationships, nothing is linear. So you better get your student hat on and start learning in depth about what works. Embrace your experimental side and start truly understanding why you're doing this, so that you can then figure out what and how to do it.
If your best case studies are the ones you see on the ad blogs, then you have proven you can read. Nothing more.