Looks pretty good, Norton has come along way since the pretty resource hungry 2006 & 2007 editions I had, think 2008 was also heavy too although I never bothered to try it out so could be wrong. Going from recent tests they have improved considerably with the last couple of editions. It will be interesting to see how this compares with Kaspersky Internet Security 2012 which is currently in beta as well.
Post that in the Beta forums then. I find it lighter than 2011 (in numbers) and 2011 is not noticeable on my computer.