This is kind of an embarrassing question for leaders. But I think there are a lot of reasons we don't see what we read about in Acts - everything from our understanding of "church", to our leadership culture, to a misunderstanding of the Holy Spirit. As I finished reading Acts a few months ago, I sensed the Spirit of God prompting me to go back (yes, I was out running at the time) and work through the meaning of the testimony of Acts for us today. Please feel free to chime in on this at the Facebook Page "Organic Church Movements" http://www.facebook.com/groups/16161960273/
I believe that the first chapter holds a key to understanding the rest of the story - it is in the words of Jesus. Like so many other things about Him and His mission, I think we have over-interpreted Him. He said a simple thing here: "You will receive power when the Holy Spirit has come upon you, and you shall be my witnesses..." That's it. No mention of gifts, miracles, signs and wonders - Then I thought, that was His point. The empowering of the Holy Spirit was not for any other reason - TO BE WITNESSES. I thought that if that is the case, everything else from here on should show that to be true.
As I would read on the chapter, even the concern with replacing Judas as an "apostelos" was all about the witness - the witness of those who had seen the life of the Messiah from His baptism to His resurrection. I don't think it's a stretch to put this also next to the last words of Jesus in Matthew to the disciples: to "...make disciples of all nations...teaching them to obey all I have commanded you...". The appointed task of disciples is to make more disciples - the role of the Holy Spirit's empowerment is all about being witnesses to the living Jesus Christ.
What I think it means for us today is that our witness of the reality of Jesus' work in our lives is the most powerful thing we have here. We can change the atmosphere around us by just saying what we have seen Jesus do. Haven't we all experienced this? Why do you think it is so hard to do? Is the enemy pushing back with all his might to stop the witness of the living Christ? Consider the power that accompanies your testimony - If we want to see what we read about of the early church, we can start here.