Brad, you really don't need to worry. Norton protects both heuristically and by definitions, and Pulse Updates are coming through regularly 24/7. Also the IE flaw has been patched, via Windows Update.
FWIW, I have my Boot Time Protection set to Aggressive which means Norton loads before anything else, giving you maximum protection.
My computer is shut down at night, and as soon as I log on, I run Live Update for the latest definitions.
Having said that, no one program can protect you 100% of the time.
Surf sensibly, look out for bundled unwanted software when you download things, and you'll be pretty much ok.
Run back up scanners like MalwareBytes, and you're well covered.
You may also want to check this thread out. Lots of good tips from other users.
http://community.norton.com/t5/Tech-Outpost/How-I-stay-safe-online/td-p/1117004
