T-Mobile isn't quite done making changes. Coming by way of a recently issued press release, the carrier has unveiled the "Simple Starter Plan." And along with this new plan being announced today, there was also mention about more changes coming shortly.
The Simple Starter Plan will be available beginning on April 12th. The plan will be $40 per moth and include unlimited talk and text with up to 500MB of 4G LTE data (with tethering). T-Mobile is pushing this one for the "value-conscious" and as we've seen before -- they have said there will be "absolutely no data overages."
T-Mobile hasn't offered specifics in terms of those other promised changes, however they did lead off with a bit about how this is "day 1of 3" and they are "on a roll again with multiple initiatives." Simply put, it seems we can expect more changes in the coming days. The other aspect here is how good T-Mobile seems to be at touting themselves above other carriers.
In this case they made it clear they are the "only major US carrier to offer a single line of 4G LTE data @ just $40 a month." To that point, we look towards AT&T who offer a plan with 300MB of data (and at a higher monthly price). Aside from the extra data and promise of no overages coming from T-Mobile, they also have the month-to-month no-contract aspect in their favor.