I'm usually not a fan of The Old Gray Lady. I'm not one for their liberal journalistic leanings but, be that as it may, I do have to say that the article written by Molly Wood hits the nail right on the head. Ms. Wood writes that the flaws of iMessage make choosing an alternate for your messaging needs, and BBM is a proper choice.
In her article, Ms. Wood highlights the shortcomings of SMS messaging. Lag, cost, failure of delivery, lack of features. Adding to the problems is a current lawsuit against Apple for the shortcomings of iMessage and the failure to deliver messages when a user switches from an Apple phone to a non-Apple phone. Also doubts are thrown up about the iPhone security as well as keying in on the unreliability of iMessage to deliver messages on time.
The article points out that BBM is the choice of the devoted and has earned it's reputation because of it's security and does everything iMessage does but never touches your text messages. It is really a no-brainer to see that with the ability to know instantly when your messages are delivered and read, video chat, voice calling and groups, your choice should be BBM. All of these things, it seems that Apple has decided to "borrow" for their own.