I'm honestly not trying to be cynical or pessimistic here. I love Smash. As a little background, I did all of the following in the leadup/post release of Smash 4:
- Paid $10 to get someone's Club Nintendo early demo for the 3DS release.
- Bought a $20 grip for my XL.
- Bought the 3DS version from the eShop in the middle of the night of release (couldn't get the eShop to work at midnight) at $40.
- Bought two more Wavebirds to have four wireless GC controllers at $30 each.
- Bought two Smash-themed wired controllers to have four wired options at $30 each.
- Bought a GC adapter (which I'd have bought two in hindsight) at $20.
- Bought a LAN adapter for my Wii U to have a wired option at $13.
- Bought a powered USB hub so that I had enough ports for the GC adapter, my external HDD, and this hub at $15.
- Bought a long ethernet cable to run from the router to the Wii U at $10.
- Preloaded the game from the eShop at $60.
So, all in all, after tax and what not, I've spent over $300 on stuff just for Smash. I don't mean stuff that I could optionally include like the cost of the console itself or the HDD I already bought or the mortgage payment I make so that I have a house to play Smash in, I mean stuff that I bought for no other reason than to play Smash and improve that experience.
Now, obviously, that doesn't make me an authority on the situation. If you and your friends all love 8 player Smash, then who am I to say otherwise? Anyway, this long tangent is just to try to establish that I'm definitely not trolling here. With that out of the way, while I'll concede it's an interesting diversion that I'm glad they've added, I really don't think 8 player Smash is that compelling of a feature. It's just a chaotic mess at that point. Fun in small bursts, but hardly where the game shines, and often times impractical to set up. It really feels like a "we were to busy asking whether we could do it that we didn't stop to answer whether we should" situation to me.
Mind you, local multi is a feather in Nintendo's cap. They've focused hard on it, and if that experience is what you're mainly looking for, then the Wii U is an excellent choice. But I don't think touting Smash's wacky 8 player mode really cements its position as the local multi king. That mode -- in my humble opinion -- gets old quick. And I've only played with six so far. I don't find myself thinking "call me when Street Fighter V has an 8 player mode; in the meantime me and my seven BFFs are going to stick to Smash 4."