Short answer: No.
Long answe: Hell no. That would suck horribly. They should continue the way they're making GC games at the moment: with new and original characters with a background instead of some random 10 year olds who have nothing better to do than going on a journey and coincedental running into an evil team who they just stop without effort. Despite what everyone says, Colleseum and XD were actually original, had a good plotline and was good instead of the same old boring, inspiration-less, unoriginal, plotless, pointless, actually awfull in comparison to Colloseum and XD if it weren't an RPG, 2-D games. And just putting the same game in 3-D wouldn't make it any better.
Even if they just put the characters in a whole new story it would suck awfully. Their journey has ended, so do like it has been done with all other games and just make new characters and let the old ones not appear at all except for one single battle.
And you do realise that Saphire/May's boobs aren't as big in 3-D as they were in the anime, right?
The only plusses would be Flannery, the Beauties and Swimmers ♀ in 3-D.