I don't put it past TNA to greenlight this ppv and bank on it to fail miserably just to prove to themselves in some insanely warped way that bringing in Paul Heyman wouldn't improve business, despite Paul stating multiple times that he has no interest in and wouldn't book an ECW invasion.
An all ECW ppv is completely idiotic, regardless of who's booking it (and this is coming from a long time ECW original fan!). You'd be keeping 95% of your worthwhile roster off the ppv by doing so. It just smacks again of TNA grasping at straws, living in the past and hoping to relive some great moment while drawing fans instead being the innovator of today's wrestling. Not to mention that before this ECW angle began, most of the wrestlers involved weren't even being used on camera. It's just a really bad idea and it doesn't really surprise me that TNA's running with it.
As for Jerry Lynn vs. RVD, I have to admit I am interested to see if both men can pull off a great match. It's the ECW equivalent of HBK/Taker, to a degree. BUT NOT while RVD has the TNA title. Bringing Jerry in for what seems like a one-off appearance in a title match kills any dramatic possiblities you could build that he might actually win the match.