...when they treated Linux and mobile platforms in general as second if not third class citizens.

Corporations such as Nokia are fed up having to pay large licence fees to Adobe for shit ports of Flash for their Linux platforms (ie. Internet Tablets) and Nokia probably don't want to get into the same mess if/when AIR becomes successful. Hence Nokia backing Silverlight, which has solid multi-platform support from the get-go, should put a fire under Adobe and give them cause to reconsider the mistakes they have made in the past.

It's not over for Adobe, Flash and AIR by a long shot but Adobe need to get on board the Linux and mobile platform train that is currently leaving the platform. Open sourcing their Flash Player wouldn't be a bad idea either.