Future Gohan=WIN. Also, it pretty much confirms that he'll be in Sparking 3. I mean, he's in this game. I'll seriously punch someone if he's not in S3.
No it doesn't.
The Shin Budokai games run on the Budoaki engine and are developed by Dimps, the Sparking games (use an entirely different engine and) are developed by Spike!
The only thing the two have in common in terms of development is that they share the same producer, but other then the development of both is completely different.
Also note that not everything in SB1 appeared in Sparking Neo.
Hey, Gohan should not have that other arm, if he is in Sparking 3! Then, if its like this his second costume better have only one arm!
It be a pain in the ass to program (which I explained earlier and) which is why they didn't/won't do it.
The grahpics is like Budokai 3
That's cause it's running on the same engine, just like the first Shin Budokai.
and how is Vegeta and Gohan alive? Why is Broly there?
It's not all that difficult.
1) This game is a sequel to Shin Budokai and will include everything the first game did plus more, and the first game (had a number of changes compared to B3) and featured various characters like Vegeta, Broly, etc, so they're of course going to be in this game too as they're just adding to what's already been made.
2) In terms of the storyline they can really do anything as the alternate future allows for a lot of freedom in terms of story. For instance they will most likely bring all the dead characters back to life (probaly with the Namekian dragonballs) because if they don't the story mode is only gonna last 5 mins, ie they need to find a way to work every playable character into the plot (just like they did with the first game) and considering a good chunk of the heroes are characters who've already died the only way that's going to happen is if (in the story) they're brought back to life.
3) As for Broly, if you remember in Movie 8, they came to Earth to get Vegeta and kill him so that Paragus could eventually rule over Earth, but considering Vegeta is dead and Earth is a wasteland in the alternate future there would be no reason for that plotline to carry out, not during the time it was supposed to take place anyway. However given that Broly is a playable character they'll work him into the plot somehow, and I'm betting he'll be one of the people Babidi gets power from to release Buu, before coming to Earth.
Whatever they do with the story it will be crazy just like the first game, but they will find someway to work everyone into the storyline somehow regradless of the possibilities.