I get an email like Arik's every day or two. He wrote:
The problem I see is that Careers 2.0 give advantage to developers with high Stack Overflow statistics (which I guess was the point, showing that you know stuff). Unfortunately, SO succeeded so well, that practically no good question remained unanswered. Thus, gaining a respectful reputation in SO is practically impossible these days. Which gives an unfair advantage to veteran SO users.
First of all, whoa... have you seen the Stack Overflow homepage lately? We're getting about 4,000--four thousand!--questions a day. There are puh-LENTY of opportunities to find a question to answer.
But more importantly, sheer reputation scores are not how Careers 2.0 works, and it's not what Careers 2.0 hiring managers are looking for. What they want to see is a sample of your work. They don't need to see your answers to 7000 questions--they want to see five really good ones.
A Careers 2.0 profile is designed to let you highlight your best software development work. You can link to open source projects, link to your favorite books, link to your blog posts, but most importantly, you can pick some of your favorite answers that you wrote on Stack Overflow and link to them. Four or five great answers is enough to prove to a recruiter that you know your stuff. (Here's what my profile looks like. I'm not actually on the job market; please don't try to hire me!)
If you want to build up a decent Careers 2.0 profile without spending hours a day, I recommend looking for five unanswered questions and just overkilling the answers. There are LOTS of easy questions on Stack Overflow. They tend to drive me crazy; many of them are "do my work for me" type questions. If we had a dollar for every time someone asked how to "replace a bunch of strings in a bunch of files with another bunch of strings, in Python" we wouldn't have had to raise $18M in venture capital. There are hundreds of questions on Stack Overflow about how to replace strings. Some of them have good answers and some have bad answers but you know what I really want to see? A single, amazing, awesome, EPIC answer that kills this topic so well that it becomes the standard source on the Internet of how to write code that replaces strings. It might start with an exploration of how to use sed and goes into Knuth-like detail on searching strings efficiently. Make your answer so amazing that it gets onto Hacker News and gets dozens of upvotes. This is your chance to write one great answer which is going to prove to a hiring manager somewhere that you deserve an interview.
The theme of Stack Overflow is being awesome. Learning, teaching, and, at Careers 2.0, demonstrating your awesomeness. It's not about hiring managers who want to hire the people with the most points... it's about letting hiring managers see who you really are instead of just being a list of previous employers and schools.