I've got $5 that says they will discuss JUST that...wait, I won't have $5 if they do that...well, you get the point. What'll be on the face of the bill? Hmmm...could it be...hm...well....SATAN???
It's only the Chinese that want a world currency - the reason being that they bought all the US debt:
http://www.thecreditcruncher.com/2009/03/what-can-g20-achieve.html
Their problem is they bought US treasury debt in US dollars, and don't want to see it devalued by 'quantitative easing' - for fairly obvious reasons.
It won't happen - not for a LONG time, although it's fair to say that China do have some bargaining tools in the form of trillions of dollars that the US have borrowed...maybe they can now do whatever they want??
Personally I think if the UK won't accept the EURO, I can't see us jumping for the International Yen Dollar thingy which should probably have a picture of Marx with a great big 'I told you so' banner in his hand. We could call it the Soviet Dollar just to rub it in.
http://www.thecreditcruncher.com/2009/03/marx-was-right.html
(BTW, I'm not advocating Socialism - just read the article...)
Supplementary answer: will I accept it? - If you can take it to the bank, I'll accept it - wait a minute... If you can stash it in your mattress, I'll accept it (or if it can be paid straight into my paypal account...)