The quick and dirty is this: Basel has adopted surprisingly strong capital requirements (the amount of money financial institutions need to keep on hand). That's a major victory for U.S. Treasury Secretary Timothy Geithner who faced opposition from many European countries. Given that the financial regulation bill passed by Congress earlier this year contained no hard capital requirements, this iteration of Basel is arguably a bigger achievement for supporters of stricter standards.
Felix Salmon from Reuters explains the emerging deal:
"Possibly the most important thing here is the existence of the first column, setting minimum standards for common equity -- which is also known as core Tier 1 capital. Such standards did exist in the past, but they were set extremely low, at just 2%, and so were generally ignored. As of now, common equity is the main thing that matters. No more throwing any old garbage into the Tier 1 bucket and calling it capital: the new standards for common equity are significantly tougher than the old standards for Tier 1 capital in total. The absolute bare minimum for core Tier 1 capital is 4.5%, and the new minimum for Tier 1 capital in general has now been raised to 6%. The minimum for Tier 2 remains at 8%. But that’s just the beginning."If you understood that and want more, see Salmon's complete rundown here.