The website 911HTC, a sort of well known and more underground site, has posted what appears to be the Sprint ROM for the upcoming HTC 7 Pro. The site generally has a very good track record for these releases so we're betting on legit here. It's also not too uncommon to find ROMs of unreleased devices making their way onto the 'nets due to HTC's FTP servers, which host the ROM files (something for which they're trying to combat).
The ROM's name is: [WP7]RUU_Gold_C_Sprint_WWE_1.25.651.01_1.51.00_RELEASE.exe and what is significant is the "RELEASE" part which usually implies a finalized build.
No, there's nothing in the ROM that mentions a release date, but it is a good sign that we're inching closer to the phone making an official appearance (something that looks to be not happening here in Barcelona).