I'm not sure what you mean by "no need for antivirus or any of that nonsense"
If you mean you don't need anti virus software, then you're wrong. Viruses these days can get past the firewall as they appear relatively harmless but infact can spy and corrupt your entire system...... so you need to have active programs that look for the little buggers or you'll end up in a world of hurt.
And if you mean the pre-loaded crap that comes with most laptops.. it's really easy to clean that off.
But even Mac snobs need antivirus software:
New Mac malware epidemic exploits weaknesses in Apple ecosystem | ZDNet (story about the Flashback exploit for Java which took Apple months to fix)
1 in 5 Macs has malware on it. Does yours? | Naked Security
The Macís Malware Problem Just Got A Lot Worse & Okay, Maybe This Mac Security Problem is Real (stories about MacGuard/Mac Protector malware/phishing scam amalgam)