If it forces Vince to change what the WWE does then we as fans still win, as we get some decent entertainment from WWE (something closer to what it's been like before 06/07).
Whilst I agree with what you say there the rest of it I dont, I've just watched the Hogan debut show and personally thought it was **** poor to be totally honest.
Comparing the two shows TNA and Raw on TNA you had in ring promo's that were pretty much a mirror image of 2002 when Hogan and the NWO returned to the WWE whereas over on RAW you had something totally new and fresh and something that was truly definitive in the history of Wrestling - the return of Bret Hart and quite possibly the first face to face confrontation between him and HBK in 13 years - that was something that had me on the edge of my seat whereas listening to Hogan, Hall, Nash and Bischoff was just like watching a video of WCW 10+ years ago.
The only thing that made me watch TNA was Jeff Hardy's appearance as lets face it that was the only real surprise of the show and having watched it showed where TNA under this Hogan era have gone wrong already, Jeff Hardy leaving the WWE going back to TNA should have been the focal point of the show but instead it was stuck on first, has setup a possible feud/angle with no one of real importance and by the end of the night was probably just an after thought of the whole show. Anyone with half a brain should have really capitalised on bringing in the WWE's most over babyface but instead in took a backseat to a bunch of hasbeens.
Upon reading what happened on TNA at the beginning of the week and then looking at all the big names in the company now with Hogan, Flair, Bischoff, J.Hardy & Angle you would think that maybe they will start challenging the WWE but even with the WWE's current product going through one of it's poorest spells it's still leaps and bounds over the second rate show/company that is TNA.
The whole production of the TNA product is just cheap and tacky much like WCW was, back when WWE last had competition they took their product to another level but TNA are so far behind the WWE at the moment even with the latest influx of established names I cant see why the WWE would worry about TNA whatsoever. To be brutally honest of the WWE sorted out their own product and got rid of the likes of Cena & Sheamus out of their World Title picture on their A show TNA wouldn't even get a mention such would the quality the WWE have over TNA because as like you said rypt the only thing that TNA might have over the WWE right now is the in-ring product.