HP’s CEO Meg Whitman has just announced that the webOS code will be open-sourced ! This is great news for the open-source community after the Odyssey announcement. This means two things : either HP takes open-source seriously and hopes to revive webOS through that move, or it prefers to drop the development entirely to the open-source community. I would tend to the first solution for two reasons : first, HP controls the update servers for all devices and hence a majority of webOS devices will remain updated through HP channels. Second, if HP wanted to drop webOS entirely, they would have sold it to another company (such as Amazon, who is eager to sell tablets).
WebOS was already based on Linux and on open-source software stack (with, for example, a standard Linux kernel, LVM, etc.). This change will benefit the community with a great component for UI development, as well as webOS users, who will benefit from more applications and a broader ecosystem in the future.