There’s a quick one page recap from Gartner about the 2008 security software vendor market-share breakdown. As in 2007 Symantec is still clearly the market leader with 22% (falling 2% from 2007). In second place is McAfee with 10%.
Not surprisingly the area with the most growth is SIEM - security information and event management. As everyone is preaching, including the maker of Snort, most companies have monitoring in place and are generating anywhere from a hundred to a hundred thousand events a week but more times than not NO ONE IS MONITORING THESE EVENTS.
Read the complete market-share breakdown here: http://www.gartner.com/it/page.jsp?id=1031712