OverThereTooMuch,
Read more carefully. There's a FAQ on the T-Mobile site that states that T-Mobile will be selling FULL SPEED international roaming packs (whatever the foreign network is capable of either HSPA+21 or HSPA+42 dual carrier, no LTE roaming at this time). Most expensive is $50 for 500MB of international data roaming FULL SPEED for 2 weeks. This is cheaper than Verizon ($25 every 100MB) or AT&T ($60 for 300MB). There is also a slightly cheaper and more data allowance plan restricted to just Canada/Mexico (cross border fiber that is cheaper to deliver versus undersea).
I'm assuming T-Mobile USA upgraded their IT back-end to offer this (IPX, GRX, etc.).
I'm just happy about the 0.20/minute in 100+ countries. All the countries I travel to or wish to visit are on there (Latin America, North America, Europe, Asia). Most of the missing countries seem to be in Africa.