After AT&T backed out of its T-Mobile acquisition last year, a lot of folks wondered what the future would hold for the Deutsche Telekom-owned carrier. Fast forward two and a half months later, and things are not looking good.

T-Mobile noted this morning that its last quarter was one of the toughest in company history. With no iPhone, and a questionable future, nearly a million of its subscribers jumped ship during the three month period…

AllThingsD reports:

“For T-Mobile USA, the past year was characterized by significant challenges, particularly in the fourth quarter, following the market launch of the new Apple iPhone model by the three major national competitors in October,” T-Mobile said. In the fourth quarter alone, T-Mobile USA lost 802,000 contact customers.”

This reminds us a lot of the comments made by Sprint’s CEO Dan Hesse last year, before Sprint became an iPhone partner. The carrier admitted on a number of occasions that it felt that a majority of its defecting customers left in search of the iPhone. That’s pretty crazy when you think about it — a carrier citing a single handset as a major factor in its poor performance.

The bad news for T-Mobile is that things don’t look like they’ll be getting better anytime soon. With its awkward AWS-banded network, the carrier is likely to continue to be the only major operator in the US to not offer the iPhone. And it’s not planning on launching its LTE network until sometime in 2013. Ouch.