This year seems to be an important year for Rich internet application (RIA) as many new releases/features are due to be out. Among them, three camps are worth watching:

• Adobe AIR: currently support Mac OS X and Windows, Linux version is expected to be released in the second half of 2008
• Java: particularly JavaFX. Let's see if Sun can really deliver something less frustrating this time.
• Microsoft Silverlight: I just hope MS keeps up the promise to make it real cross-platform.

planet-ria.org seems to be a good place to get the latest information about RIA. Here is a a good slide on RIA I found on this site.