SprintFeed has posted a shot of what appears to be a changelog for an upcoming Android update for Sprint's Nexus S 4G -- build GRJ90 -- that should bring a WiMAX settings widget, TTY support, and both "improved Wi-Fi connectivity" and "signal acquisition," among other things. That's great news considering the phone's been widely dinged for having weak signal reception, but it's not the biggest news: that would be the fact that the phone's NFC secure element will be enabled for the first time, which means Google Wallet's contactless payments (which rely on the NFC security silicon embedded inside the Nexus S series) will be able to operate for the first time. It's hard to say just how quickly Google will be looking to launch its Wallet trial after this update happens, but they'd been promising a summer kickoff -- and New York's all-too-short summer season is already well underway. SprintFeed's leak indicates an initial rollout to Nexus S 4G customers starting next Monday, July 11th, with the full subscriber base coming on board over the course of four days... so we're looking at less than a week's wait if this all pans out. Stay tuned.