What I heard for WE8 for US is.. pretty much same deal with PES4 as far as game mechanic is concerned.  Perhaps a bit of update for the roster, but I am not sure it will be as updated as LE version which is coming out in Japan in March 3rd.  LE, on the other hand is known to have fundamentally updated player animations, updates and other goodies besides online play, which will be the biggest merit for me.
Last time was similar - WE7 JP - PES3 - WE7 Inter (US) - WE7 Inter (Kor) - WE7 Inter (JP).  WE7 Int (JP) was the most updated one, to the degree of saying "final evolution" ish.  I am assuming that LE will be the same + online play.
lachesis