I must say I do miss his old Pokemon, especially as someone who's watched the whole series from the first episode. It would be good to see the likes of Butterfree, Pidgeot, Kingler etc again.
The problem is that due to the new audience that Pokemon is now catered for I think the writers will be reluctant to bring in references to any of his past adventures. I read somewhere that in the "Pika vs Goliath" episode from Battle Dimension, they edited out the flashback the scene so it wouldn't show Misty, because they thought that the people who would be watching the episode now would not know who she was. If they are going that far to not bring up old friends, I'm not sure what hope there is to see the likes of Pidgeot again. I think at the very best we may see some of his old pokemon come back to help him out once he eventually gets his eight badges and competes in the Sinnoh Championships, similar to what happened in the Johto championships where the likes of Muk, Snorlax, Squirtle etc all came back to help him.