International Data Roaming

When will T-Mobile US offer reasonable International Data Roaming rates?  $15 a megabite is a joke.  ATT offers a monthly 120 MB international roaming package for $30, i.e., 25 cents a MB.  Maxroam offers international data roaming as used (no plan) for 49 Euro cents, e.g., 65 cents a MB.

I use MaxRoam and am thinking of switching from T-Mobile to ATT.