I guess that the next set of major attacks won't be targetted at pwning someone's PC but rather using their browser as a vehicle to attack web services, do DDOS

I guess that the next set of major attacks won't be targetted at pwning someone's PC but rather using their browser as a vehicle to attack web services, do DDOS and steal info from servers. However I used to run IE6 + Flash on WinXP without any anti-virus and never remember any significant problems with malware on my computer (witnessed a lot on other people's though).