According to F4WOnline.com, Ring of Honor tag team members Jay and Mark Briscoe, known as The Briscoe Brothers, were offered WWE deals awhile back, only to have Ring of Honor block the duo from accepting the deals as they were under contract to ROH.
Additionally, it's being said that ROH star Adam Cole was offered a deal by WWE, which was also blocked by ROH.
For what it's worth, when Ring of Honor was purchased by Sinclair Broadcasting Group back in May of 2011, COO Joe Koff had the following to say about talent moving from ROH to WWE:
I'd like to believe our guys are content to wrestle with the ROH brand, strategy, and work, but I wouldn't want to stop them if WWE came calling. That is the pinnacle. This is no different than working AAA ball and the Big Show (Major League Baseball) calls them.
Had no idea the WWE were even interested in the Briscos. Wonder if it'll fuck with a future deal now.