http://stlhops.com/ has the list of what they are offering this year. Tickets are going to be sold out very soon. If you have the chance to go, take it!
I attended the first Lupulin Carnival and had an absolute blast! Missed last year and will regrettably not be able to attend this year but from the sound of it, this event continues to grow every year. Quite the line-up of fantastic breweries! 4 Hands is one of my favorite local spots to be!
I went the last two years. It's one of my favorite beer festivals. Unfortunately, the judging for the first round of the NHC is the same weekend and I feel obligated to do that. Next year!