Microsoft has announced in its latest security advisory that it will be addressing 49 vulnerabilities with patches tomorrow. This is the largest number of vulnerabilities to date addressed in one day.
Ten of the patches are deemed "critical", and the patches will address issues in Microsoft OS software from XP to Windows 7, Server OSes, and Applications such as their Office suite.
So if your Windows computer is slow tomorrow, or your network seems sluggish, it may be downloading the plethora of patches that will be released tomorrow morning. If your machine is set to receive updates overnight, be sure to leave it on tomorrow and to reboot it first thing in the morning.