Slightly confused history
T-Mobile's purchase of One2One (and another networks in other countries) was fuelled by the privatisation and IPO of Deutsche Telekom, along with the general goldrush of telecoms and internet companies at the turn of the millennium. Telekom's Ron Sommer was just as odious as Vodafone's Chris Gent.
It was also Mannesmann's purchase of Orange that spurred Vodafone to take it over (at ruinous expense to Vodafone's shareholders but at great profit to Mannesmann's shareholders like Deutsche Bank and Hutchison Whampoa who saw a 400 % return within a year). Mannesmann also came with dowry of a part of AirTouch making the sale of Verizon over ten years later less impressive than portrayed in the article.
One has to question the value of buying into the US market at the moment. Money-printing has inflated shareprices and profits seem to have reached their maximum. The market is much less competitive than anywhere else which suggests that margins, and thus profits, will decline. Furthermore, T-Mobile needs a lot of money spending on building out the infrastructure in order to compete with AT&T, Verizon and Softbank.
T-Mobile meanwhile is doing a reasonable job on its own of raising its profile and growing its customer base. Being number 3 does make it a possible target but I suspect the price will still be too much for many. Make take a real outsider such as say Google or China Mobile with pockets deep enough to pay for the infrastructure and keen on disrupting the status quo.