In terms of the TV show, the seasons that'll soon be available to stream inclue the first one, Indigo League, which was originally aired between 1997 and 1999 in Japan and North America. Indigo League will be available to Netflix owners in Canada, Ireland, the UK and the US.
The other season that's arriving tomorrow is the 14th one, Black and White, which first aired in Japan in 2010 after the release of the similarly titled games on DS. Season 14 will be coming to all Netflix territories.
Though an alternative Poke-offering in the US remains the one offered by Hulu, this isn't available outside North America. Hopefully, this'll be the start of a beautiful relationship between Pokemon and Netflix, and we'll see the number of available seasons grow as time goes on.