I have known Paul Ryan since he started in Washington as a member of the staff of Senator Bob Kasten in 1990, then as legislator director for freshman congressman Sam Brownback in 1994, and then when he got elected to Congress.  Here's something funny: he gets just as excited in private as he was in public.  He energizes a room.  No wasted time, let's get this done.  

This is a guy who reads books, who studies details and yet grasps the big picture.  Bluntly said, he's also someone who has improved his communication skills.  As he had to work to convince other members of congress to back his budget, he honed his arguments about the risk, the details and his arguments.  Most importantly, he lived with his family in Wisconsin when Congress wasn't voting.  And he just circled his district over and over and over.  He was always considered among the hardest-working congressmen.  Not in going to receptions and Washington events but in holding open town meetings where constituents could hear each other and his responses to them.  Stopping in coffee shops and Rotary clubs, taking unrestricted questions under pressure and scrutiny from his neighbors.  Because he listened, and argued the points, he has developed into an extremely effective communicator.

A few technical points proving that point and why his speech was so effective.
1) Strong content (always the anchor) - everything will be free except us, how would the next four years be different, etc etc (Google quotes from his speech and then be impressed with how many really good ones there were)
2) Personal touch - talking about losing his dad when he was young, how he thought his dad would be proud of him now, with his eyes tearing btw and affecting his speech pattern which was not faked (I could see his frustration with himself, trying to fight it off, saying focus, focus - all good speakers have had such moments) and then again as he told how his mom, a young window, started a business and was his hero, again impacting his delivery pace.  This is hard to fake, not impossible, but I know Paul pretty well.  He's a focused guy, not a small talk or family talk guy.  This was real from him.  
3) Controlling his speech pattern - I talk fast.  Paul Ryan talks really fast.  Really, really fast.  You can observe people around him just lose him as his hands go and he machine gun fires points.  Some media are saying that he started slowly.  That he was nervous.  Well, duh.  Of course he was but it was more than that.  He was coached to slow down.  He speaks in bursts when addressing groups, otherwise, at his pace, the 30 minute speech would have taken 5 minutes.  He has also been trained by experience to build the momentum.  That isn't an accident.  It is passion building that gets communicated, in part, as a momentum build.  His family comments also upset his normal rhythm because it is not normal for him.  He looked over and saw his wife, his kids and his mom (the camera was completely thrown off, searching for her and at first on the wrong female - the script called to introduce her later).  Internally he likely flashed back in his life as he talked about his jobs and being fatherless and poor.  Now, Paul's brain flashes back and forward again a lot faster than the average person.  But one of the advantages of not only knowing him but having recently bought a 50 inch television and HD, is not only that you can see ever whisker but see a person's eyes closely.  As Paul moved back into the ideas, his rhythm accelerated and then hammered home his points.
4) Clearly they have 3 teleprompters: one to right, one to left, and then a center one.  The political term is this: at key points, speak to the camera directly or "make love to the camera."  Boy did he.  Intense form.  He bored in on his punch lines dead ahead and focused his passion.

Those things made a great speech.  As good as he could have given.  He is now a political rock star.