Roy being in/out does not really affect me much. But....
I really hope they take out Marth. I am extremely sick of Marth. And Ike not only looks very much like Marth, but has lots of the same moves and apparently Sakurai won't do clones. So him not getting his own character slot would please me a lot. I have nothing against the Fire Emblem character, but as a Smash Bros. fighter, he is obscenely annoying.
If they do put him, then tweak the crap out of him. The last thing I need is to online in Brawl to fight Marth 75% of the time, when there is 30+ other characters to use instead.