Blizzard has released the currency conversion rates for the upcoming Cataclysm changes. Remember that these conversions will take place when patch 4.0.1 is released. There will be a "soft cap" at the conversion, so all your work won't just disappear, but there will eventually be a hard cap. Check out the original post for a detailed explanation.
The Cataclysm currency conversion rates in brief are:
- (Emblems of Triumph + Emblems of Frost ) * 2.75