For the current vulnerability in Internet Explorer 6 and 7 which already gets actively exploited on the net, Microsoft is already testing a patch. The company is still considering whether to release the patch on the regular Patchday or out-of-band.
Meanwhile, a “Fix-it”-solution is available. With some registry changes the affected peers factory in iepeers.dll gets disabled by a mouse click. You can download it from Microsoft’s knowledgebase.