Android's already doing it but according to Bloomberg, the next generation iPhone and iPad, slated to come out this year, will carry Near Frequency Communication (NFC) technology. What this means on a broader level is that your smart device will be a wallet replacement. According to the report, Apple's made several strategic hires of NFC experts and this feature is to be used in several applications like mobile ticketing, mobile money and smart billboards. Of course, the downside of having a device that becomes your wallet is the bombardment of advertising and coupons (that if you're already frustrated with today, it'll be hellish when you make the conversion).
Who says you have to give up carrying your cash in leather?