Here's the thing......people are saying (and they're right) that with the move to MyNetworkTV coming up in September, WWE should want to have a big star at the top of Smackdown, and that's reason enough for HHH to retain, even if he only keeps it until the next ppv. But if Taker is involved, he's a bigger star than even HHH is. Logically, he'd be a better choice, then.
And if for some reason Taker does have his match, who does he face? You can't have him completely squash Shelton/Kendrick/MVP as it makes their title reigns only last a few minutes and they look terrible in the process. You can't make him squash Jeff Hardy, as you not only make Jeff look bad, but you risk turning Taker heel (tough, but the fans are ridiculously behind Hardy lately). So that brings us back to HHH retaining, as he could lose to Taker and it wouldn't be too bad.
However, do you really want to waste having Undertaker/HHH complete with a title change on a ppv that is already full of a "brand new" type of match? Typically, the smaller ppvs revolve around a midcard title possibly changing hands + some sort of gimmick match that sells the ppv outside of the primary feud. Right now, we know that there's more than a good possibility that Matt Hardy is walking out with the ECW title, and there's also a chance we could have the IC and Raw's tag team titles change hands. There's even the possibility that Hardy walks out champion, though I doubt it. And on top of that, there's the possibility that Batista takes the belt from Punk. Strictly in a business standpoint, do you want all your eggs in one basket? No. You want to spread it out. It'd make much more sense for Undertaker to receive a title shot at No Mercy against whoever walks out champion from the Smackdown Scramble...especially if its HHH or if the plan is for Taker to win the title back.
Now, I'm not a business major, but any fool knows that businesses aren't 100% about making the people happy. Would I like to see Undertaker get a title shot at Unforgiven after a scramble? Yeah. I'm sure most people would. But then what do you have for No Mercy? If you jam-pack Unforgiven, and you get a B+ or an A score, and then you have nothing left for No Mercy, and you get a D- rating, you average out to a C of some sort. Your business should be aiming for A's all the time, but its perfectly acceptable to have a steady, consistent B- if the people keep showing up, buying tickets, and ordering the ppv. Right now, Unforgiven already has 3 scramble matches that can influence people to buy the program, and although I won't be one of them, many people will. Sure, it won't be the Royal Rumble or WrestleMania, but it will do a decent job as a money-maker.
Plus, this is only one report, and how often have we seen reports like this that turn out to be changed? Wasn't Ron Killings supposed to be brought up to the main roster "around the Royal Rumble"...and then "a little bit after WrestleMania"? Haha. The way I see it going, we'll have Undertaker/Big Show instead, as a #1 contender's match, since they both don't have a title shot and they both weren't in the scramble.