[ben1040]

... which would seem to provide a $240/year incentive to just use iMessage, or twitter, or any IM system.

Assuming your conversation partners can keep tabs on what system to use. Your Android pals can't iMessage you, and using Google Talk or another IM service on an iPhone has always felt a little kludgy.

Sounds to me it's designed to drive you to one of two choices: either pay $20/month for a service you don't need, or cut it out altogether and pay 20c every time you get an SMS from someone who can't use iMessage/Twitter/Facebook messaging.

At 20c/message it doesn't take long before you end up paying as much or more than you would've been paying under an SMS plan.

[erikcw]

When iOS 5 is released, I plan on keeping my current SMS plan for a month to measure how many text I send to non-iPhone users. I'll then downgrade my plan accordingly. My guess is that I'll end up cutting my plan entirely and just paying per text. The vase majority of the people I text with frequently are iPhone users.

It would be a great move by Apple to open the iMessage protocol so Android and other smart phone OS' could participate in the exchange. Unfortunately, my guess is that this won't happen as "free texts" represent a great benefit for switching to an iPhone and opening that network to other vendors would undercut their advantage.

Predication: ATT/Verizon drastically increases the cost of bandwidth on iPhone plans to make up for the cut. We'll see...