For anyone who's never been, to describe the overall atmosphere in one line, I would say simply "entusiastic, energetic and excited". These three E's I think fall in under every fans experience of this great game. I think eSports will get very far in this aspect. To those who don't have them near you, if you can get the interest in Starcraft you really should try to organize this, even if you can't get it at a bar, some kind of venue that will allow it, hell even a small party in a house will function.
I built a media center PC a little under a year ago to watch MLG/GSL/IPL at home on my couch, I had a blast, but alone is nothing compared to a room full of people having a good time, talking, getting to know one another, and just sharing the experience. Something I'll never forget, and definitely attend in the future, hopefully bringing in more people.
The really cool thing about all of this, is how many people who didn't play were in attendance with people they knew, and just asking questions and showing general interest. Even cooler yet, my friend and I were sitting at the bar, and the bartender started asking us questions, my friend does not play, but he enjoys watching, and we have many discussions on balance, talk about games, players and he watches me on my live stream regularly, giving me tips and insight I don't notice as I play the game. The feedback and positive response from this event was fantastic. Even people who weren't gamers were watching the final game between DRG and Alicia just because of the overall excitement and enthusiasm in the room. Every time something happened we reacted, and they got more and more curious as to what could bring us to such an extreme volume and give us such a hearty, full experience.
I thank whoever came up with Barcraft to begin with, and secondly, eSports in general, the community, and last but definitely not least, the great people who organize such things for everyone to enjoy. Nobody does it for profit from my understanding, but just a sheer desire to share this experience with others. Thank you, Starcraft community, for being so fucking awesome.