No

Almost anything is possible…. if the service provider wants to offer it……

If Bell notices that Virgin is signing up a ton of prepaid clients that want it, then they might offer it too.

If Bell offers something, Telus will probably follow.

If both Telus and Bell offer data to prepaid clients, then Rogers MIGHT consider it.

If Rogers is feeling generous, they might try it out.

After a long time, and if Rogers is feeling really generous, they'll over it to the MVNOs that use the Rogers network (Speakout and PetroCan for example).

In other words, don't hold your breath.

However, it seems that Globalive is coming out with a new cellphone network in 2009. And they want to offer prepaid service first. So who knows? They might offer data plans. And if they come out with anything, the Big Three will offer it as well, just to prevent clients from switching.