I highly doubt it. If you want to use emails and applications, then you will definitely need a data plan to go with that. My assumption would be that the pay and go would be for talk time only with the currency being minutes, i.e. you pay for x number of minutes. Data plans are calculated according to how many MB of data you use in a set number of time, and emails, applications, browsing, all of that uses MB not minutes.
You'll be able to do most things, except receive email or BB Messenger. Those require a Blackberry data plan. You might not be able to use the browser either, but Opera Mini is a way to get around that. If you can get the browser working you'll obviously be able to check email on the internet, but it will not use the BB email capability.