If it really does have that many solid hours of gameplay crammed into it then it seems like that alone should give it enough grace to let it be praised.
Well, I've only really completed the first dungeon and have just made it to the first "new" area, and even now, I believe that I can assure you that the neither the story nor the gameplay are shallow; to put it into the terms you used, I would definitely say that there are several solid hours of gameplay in this installment.
As for some of the other comments about letting this one pass because it looks to play very similarly to OoT; what about the 3 or 4 installments of MGS? They aren't shockingly different in terms of gameplay, but they appear to do quite well, regardless. Also, consider GTA games - there have been 4 versions of the game that employ an identical style of gameplay, but they are also quite successful. Having said that; yes, TP does appear to resemble OoT a lot, however, despite that, it still feels very different. That could be due to the fact that the controls have really changed, but I think it's a bit more than that - you can do more with the character this time, imo, and the scope of this installment is just tons more grand than OoT's, from what I've seen thus far.
I can understand the 8.8 for the sound (though I am willing to forgive the use of MIDI tracks, as long as the music, itself, is still good), possibly for the fact that it didn't "reinvent" the series (not that it was aiming to, as far as I know; it "reinvented" the game in much the same way as a new installment of MGS would reinvent its genre, I suppose). While I don't consider myself as nit-picky, I do acknowledge the fact that there wouldn't be a good balance in the reviews if there weren't people like the guy at GameSpot who opt to take a less, for lack of a better term, "optimistic" approach and choose to point out some of the flaws that bothered him, even with hordes of Zelda fans pounding at his door, so to speak.
So, while I think the game deserves more than an 8.8, I still think it's necessary to have a variety of outlooks on the game; at the very least, it makes for some good reading.