In the past year or so, Microsoft has made a push to own the letter "Y". They changed their MSN Messenger product to something called Lync, and there was another one recently but I didn't catch the name. In fact, I suspect they bought Skype because of the y in it, perhaps as part of their plan to own that letter.
I don't know how long this trend of trying to own a letter has been going on, but I think it's safe to say perhaps about 15 years or more. It appears to be successful. Apple has been so prevalent with the i that people think Apple owns the letter i in front of any word, not just iPhone, iPod, iPad and iMac (BTW, I HATE it when people spell Mac "MAC"). However, iLuv, iHome, and iMedic are all not owned by Apple, to name just a few.
My prediction is the next letter to be owned will be the Q. This is one of the underrated letters in the English language. I mean, look at its phoneme - coopted by C and K, Q has had to work hard to carve a niche for itself by partnering with the letter U most of the time. Q is also nice and round, with an elegant flourish hanging off its end. It has a royal feel to it (almost a queenly touch), and is useful when you are very thirsty (it quenches). Qdoba is on to something. Next we will be taking a qNap (no relation to the NAS devices), buying a qCar, perhaps even conducting qBusiness (after we are done with our iBusiness).