TBH, I think Generation 5 will be the death of Pokemon. The metagame is on shaky grounds as it is with all the different types, attacks and abilities. Adding to them more will result in too much IMO, and making it impossible to have a 'good' team because there would ALWAYS be an easy way to counter a team, no matter how well-built. It'd be nice to have more Pokemon and such, but something would have to be done about the Pokemon that are already out, which would be a hard decision on what to do with them.