The New York Jets put in a waiver wire claim for Gronkowski and the Seattle Seahawks did the same thing with Murtha. However, both teams had submitted multiple claims and had prioritized them and, when each team got a higher 'ranked' claim, they gave up their bid on Detroit's two rookies.
I'm glad things worked out the way they did, as I have a feeling Gronkowski will be on the active roster at some point this season. It seems like injuries are always common with Lions tight ends. I hate to say it, but someone like Casey FitzSimmons, for example, just seems to be injury prone, and I think Gronkowski will get a shot sooner rather than later.