prepaid data plans are going to be the next big wave in mobile, and it looks like T-Mobile's getting on board -- we were just sent this employee training sheet detailing the upcoming Passes plans. All of T-Mobile's mobile broadband products are eligible, which is nice, but the plans themselves are a bit lame -- $10 gets you 100MB of data or a weeks' access, whichever comes first, $30 gets you 300MB or a a month's worth of access, while $50 nets you 1GB or 30 days. That's an odd blend of tiered data pricing and prepaid limits, and it compares poorly to T-Mobile's standard $39 / month data plan with a 5GB cap. But hey -- flexibility isn't cheap. Expect to see this one launched at CTIA for October release -- the docs say the new plans will arrive with a new Jet USB modem and a prepaid SIM card retail package as well.