Interesting. Amazon has set up pages for Blu-Ray releases of Princess Mononoke, Spirited Away, and Howl's Moving Castle. Studio Ghibli hasn't made any announcements, and Ponyo is still expected to be the studio's first feature film in BR.
Still, keep your eyes peeled for any surprise announcements in the coming weeks. If more Ghibli films are headed to Blu-Ray in 2009, we'll hear about it in Japan first. And if there are no more releases planned for this year, it's almost certain we'll see the floodgates open in 2010.
As always, caveat emptor. Thanks to GhibliWiki for posting the news.