Rose would be a decent veteran add to the right team. Not sure he is what the Knicks should be going after but makes a lot of sense for teams like the Clippers, Lakers, maybe even the Nets or Sixers. Rose probably does not have the durability to be a starter so makes more sense to add to the mix on a more established team to add depth.
I don't think the Celtics need to mess with their PG rotation right now so I doubt that the Celtics are involved in Rose talks.