So:
Cardinals get:
Heyward - 1 year of control for $8.3MM in 2015
Walden - 2 years of control for $3.0MM in 2015
Braves get:
Miller - 4 years of control for $550,000 in 2015
Jenkins - 6 years of control
So essentially we gave up one year of Heyward and two of Walden for 4 of Miller and 6 of Jenkins, and shed roughly $11MM from the 2015 payroll. Miller is a very good starting pitcher who has ace or #2 potential and has pitched like a #3 so far. Jenkins has a high ceiling but some injury issues. Overall I'd have to say this is probably a fair trade for both sides.