Here's some items for comparison:
"On July 2, 2010, the T-Mobile Sidekick was discontinued and no longer available for sale through T-Mobile. However, T-Mobile did support Sidekick Web Services until May 31, 2011."
"On February 28, 2011 tech blog Engadget reported Microsoft will discontinue Danger's cloud service on May 31, 2011. After that date, Sidekicks will no longer have access to any data services, though voice service will still function."
"On April 12, 2010, Microsoft announced two Kin models, both available online on May 6, 2010 and in stores on May 13, 2010 from Verizon Wireless for the U.S."
"Content from the Kin phone, like photos, videos and messages, was automatically synchronized to a cloud service called Kin Studio ... The kin studio was shut down as of January 2011."
Not saying any of this will happen to us, but we need to be realistic -- if webOS is shut down (and I'm not saying that's likely) -- there already are precedents for users dependent on cloud services being abandoned by other platforms. I'm sure HP would do the same.
(Quotations above from Wikipedia)