After that, you are basically done with the game except for the completion of the Pokedex. You can also battle Cynthia, the Champion of Sinnoh, in Undella Town.
Nothing that's it
Just enjoy Pokemon black and white! catch your favorite Pokemon, do global trades/battles or battle your friends! Have fun!
catch "em all
yes you have to find all of the seven to catch rayquaza in pokemon white
nothing.
Unfortunately, nothing happens.
Yo mammas house
You don't.
nothing that's y i just stay with Pokemon ss or hg
Not too much, go to White Forrest, catch all the pokemon. There is not any other story lines that I'm aware of
If you found all 8 sages than she will be in professor Junipers lab and you can battle her everyday (her pokemon are crap though)
Sadly after months (minutes :D ) of research, I have finally accepted that Ghetsis cannot be found even after you find all the sages in Pokemon Black/White. There are rumours though that he has been spotted near Black City/White Forest, depending on which game you have.