At last count 4,617 Twitterers are following me(@admutum) on Twitter and I am currently following 4,262 as well.
A friend recently asked me why I was following so many. According to her, it would simply be impossible to keep up with all the tweets and was the reason why she was only following slightly more than 100 people.
Of course it would be practically impossible to keep with all the tweets in real time. For example, there were over 100 new tweets in slightly over a minute which is not really much considering that I am following over 4K Twitterers. I also have a policy of following back almost anyone who follows me. And that is precisely why we have lists - I have listed the people I follow into different categories including academics, blogger friends, family, etc. Furthermore, I am managing 2 more Twitter accounts as well. This is precisely the reason we have Tweetdeck which allows you to manage multiple Twitter accounts and the Tweets you follow.
Anyway, I aim to have 5000+ followers by the end of this year and may be 10000+ followers soon afterwards.