Just saw the release making it official that Wayne Jackson is stepping down at Sourcefire.  Having seen a few of these kinds of situations but not having any inside information, it looks to me like a mutual decision and probably tied to earnings and performance versus market expectations.  In any event, Wayne has done a great job of taking Sourcefire from a good open source project to a public company.  As much as Marty is the lightening bolt and thought leader over there, Wayne brought a steady hand and sense of maturity to the company.  He has much to be proud of in his work on this one.

With a new CEO search underway, I would imagine they are going to look for someone with public company CEO experience to help guide Sourcefire through a rocky market and make up for a history of missing street expectations.  At the same time Wayne's resignation was announced of course Sourcefire also announced another quarter where they missed the numbers. Their stock is down almost a dollar off of their 6.54 closing price.  This brings their market cap down below 150m I would bet.  Tough luck for a company that actually is executing. I think it has more to do with setting the right expectations with the street than it does with the companies market share and such. 

In any event, with a new CEO coming in you can be sure there will be other changes afoot at Sourcefire.  Good luck to you Wayne on your future endeavors, you have accomplished much!